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Meriläinen E, Efimova E, Santala V, Santala S. Carbon-wise utilization of lignin-related compounds by synergistically employing anaerobic and aerobic bacteria. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:78. [PMID: 38851749 PMCID: PMC11161944 DOI: 10.1186/s13068-024-02526-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
BACKGROUND Lignin is a highly abundant but strongly underutilized natural resource that could serve as a sustainable feedstock for producing chemicals by microbial cell factories. Because of the heterogeneous nature of the lignin feedstocks, the biological upgrading of lignin relying on the metabolic routes of aerobic bacteria is currently considered as the most promising approach. However, the limited substrate range and the inefficient catabolism of the production hosts hinder the upgrading of lignin-related aromatics. Particularly, the aerobic O-demethylation of the methoxyl groups in aromatic substrates is energy-limited, inhibits growth, and results in carbon loss in the form of CO2. RESULTS In this study, we present a novel approach for carbon-wise utilization of lignin-related aromatics by the integration of anaerobic and aerobic metabolisms. In practice, we employed an acetogenic bacterium Acetobacterium woodii for anaerobic O-demethylation of aromatic compounds, which distinctively differs from the aerobic O-demethylation; in the process, the carbon from the methoxyl groups is fixed together with CO2 to form acetate, while the aromatic ring remains unchanged. These accessible end-metabolites were then utilized by an aerobic bacterium Acinetobacter baylyi ADP1. By utilizing this cocultivation approach, we demonstrated an upgrading of guaiacol, an abundant but inaccessible substrate to most microbes, into a plastic precursor muconate, with a nearly equimolar yields (0.9 mol/mol in a small-scale cultivation and 1.0 mol/mol in a one-pot bioreactor cultivation). The process required only a minor genetic engineering, namely a single gene knock-out. Noticeably, by employing a metabolic integration of the two bacteria, it was possible to produce biomass and muconate by utilizing only CO2 and guaiacol as carbon sources. CONCLUSIONS By the novel approach, we were able to overcome the issues related to aerobic O-demethylation of methoxylated aromatic substrates and demonstrated carbon-wise conversion of lignin-related aromatics to products with yields unattainable by aerobic processes. This study highlights the power of synergistic integration of distinctive metabolic features of bacteria, thus unlocking new opportunities for harnessing microbial cocultures in upgrading challenging feedstocks.
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Affiliation(s)
- Ella Meriläinen
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Ville Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Korkeakoulunkatu 8, 33720, Tampere, Finland.
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2
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Ma S, Su T, Lu X, Qi Q. Bacterial genome reduction for optimal chassis of synthetic biology: a review. Crit Rev Biotechnol 2024; 44:660-673. [PMID: 37380345 DOI: 10.1080/07388551.2023.2208285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/13/2022] [Accepted: 02/20/2023] [Indexed: 06/30/2023]
Abstract
Bacteria with streamlined genomes, that harbor full functional genes for essential metabolic networks, are able to synthesize the desired products more effectively and thus have advantages as production platforms in industrial applications. To obtain streamlined chassis genomes, a large amount of effort has been made to reduce existing bacterial genomes. This work falls into two categories: rational and random reduction. The identification of essential gene sets and the emergence of various genome-deletion techniques have greatly promoted genome reduction in many bacteria over the past few decades. Some of the constructed genomes possessed desirable properties for industrial applications, such as: increased genome stability, transformation capacity, cell growth, and biomaterial productivity. The decreased growth and perturbations in physiological phenotype of some genome-reduced strains may limit their applications as optimized cell factories. This review presents an assessment of the advancements made to date in bacterial genome reduction to construct optimal chassis for synthetic biology, including: the identification of essential gene sets, the genome-deletion techniques, the properties and industrial applications of artificially streamlined genomes, the obstacles encountered in constructing reduced genomes, and the future perspectives.
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Affiliation(s)
- Shuai Ma
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, P. R. China
| | - Tianyuan Su
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, P. R. China
| | - Xuemei Lu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, P. R. China
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, P. R. China
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3
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Enright AL, Heelan WJ, Ward RD, Peters JM. CRISPRi functional genomics in bacteria and its application to medical and industrial research. Microbiol Mol Biol Rev 2024:e0017022. [PMID: 38809084 DOI: 10.1128/mmbr.00170-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024] Open
Abstract
SUMMARYFunctional genomics is the use of systematic gene perturbation approaches to determine the contributions of genes under conditions of interest. Although functional genomic strategies have been used in bacteria for decades, recent studies have taken advantage of CRISPR (clustered regularly interspaced short palindromic repeats) technologies, such as CRISPRi (CRISPR interference), that are capable of precisely modulating expression of all genes in the genome. Here, we discuss and review the use of CRISPRi and related technologies for bacterial functional genomics. We discuss the strengths and weaknesses of CRISPRi as well as design considerations for CRISPRi genetic screens. We also review examples of how CRISPRi screens have defined relevant genetic targets for medical and industrial applications. Finally, we outline a few of the many possible directions that could be pursued using CRISPR-based functional genomics in bacteria. Our view is that the most exciting screens and discoveries are yet to come.
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Affiliation(s)
- Amy L Enright
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
- DOE Great Lakes Bioenergy Research Center University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - William J Heelan
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Ryan D Ward
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- DOE Great Lakes Bioenergy Research Center University of Wisconsin-Madison, Madison, Wisconsin, USA
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jason M Peters
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, Madison, Wisconsin, USA
- DOE Great Lakes Bioenergy Research Center University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, Wisconsin, USA
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4
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Liljegren MM, Gama JA, Johnsen PJ, Harms K. The recombination initiation functions DprA and RecFOR suppress microindel mutations in Acinetobacter baylyi ADP1. Mol Microbiol 2024. [PMID: 38760330 DOI: 10.1111/mmi.15277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 04/24/2024] [Accepted: 04/26/2024] [Indexed: 05/19/2024]
Abstract
Short-Patch Double Illegitimate Recombination (SPDIR) has been recently identified as a rare mutation mechanism. During SPDIR, ectopic DNA single-strands anneal with genomic DNA at microhomologies and get integrated during DNA replication, presumably acting as primers for Okazaki fragments. The resulting microindel mutations are highly variable in size and sequence. In the soil bacterium Acinetobacter baylyi, SPDIR is tightly controlled by genome maintenance functions including RecA. It is thought that RecA scavenges DNA single-strands and renders them unable to anneal. To further elucidate the role of RecA in this process, we investigate the roles of the upstream functions DprA, RecFOR, and RecBCD, all of which load DNA single-strands with RecA. Here we show that all three functions suppress SPDIR mutations in the wildtype to levels below the detection limit. While SPDIR mutations are slightly elevated in the absence of DprA, they are strongly increased in the absence of both DprA and RecA. This SPDIR-avoiding function of DprA is not related to its role in natural transformation. These results suggest a function for DprA in combination with RecA to avoid potentially harmful microindel mutations, and offer an explanation for the ubiquity of dprA in the genomes of naturally non-transformable bacteria.
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Affiliation(s)
- Mikkel M Liljegren
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
| | - João A Gama
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Madrid, Spain
| | - Pål J Johnsen
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
| | - Klaus Harms
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
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5
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Liu C, Choi B, Efimova E, Nygård Y, Santala S. Enhanced upgrading of lignocellulosic substrates by coculture of Saccharomyces cerevisiae and Acinetobacter baylyi ADP1. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:61. [PMID: 38711153 DOI: 10.1186/s13068-024-02510-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 04/23/2024] [Indexed: 05/08/2024]
Abstract
BACKGROUND Lignocellulosic biomass as feedstock has a huge potential for biochemical production. Still, efficient utilization of hydrolysates derived from lignocellulose is challenged by their complex and heterogeneous composition and the presence of inhibitory compounds, such as furan aldehydes. Using microbial consortia where two specialized microbes complement each other could serve as a potential approach to improve the efficiency of lignocellulosic biomass upgrading. RESULTS This study describes the simultaneous inhibitor detoxification and production of lactic acid and wax esters from a synthetic lignocellulosic hydrolysate by a defined coculture of engineered Saccharomyces cerevisiae and Acinetobacter baylyi ADP1. A. baylyi ADP1 showed efficient bioconversion of furan aldehydes present in the hydrolysate, namely furfural and 5-hydroxymethylfurfural, and did not compete for substrates with S. cerevisiae, highlighting its potential as a coculture partner. Furthermore, the remaining carbon sources and byproducts of S. cerevisiae were directed to wax ester production by A. baylyi ADP1. The lactic acid productivity of S. cerevisiae was improved approximately 1.5-fold (to 0.41 ± 0.08 g/L/h) in the coculture with A. baylyi ADP1, compared to a monoculture of S. cerevisiae. CONCLUSION The coculture of yeast and bacterium was shown to improve the consumption of lignocellulosic substrates and the productivity of lactic acid from a synthetic lignocellulosic hydrolysate. The high detoxification capacity and the ability to produce high-value products by A. baylyi ADP1 demonstrates the strain to be a potential candidate for coculture to increase production efficiency and economics of S. cerevisiae fermentations.
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Affiliation(s)
- Changshuo Liu
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Tampere, Finland
| | - Bohyun Choi
- Department of Life Sciences, Industrial Biotechnology, Chalmers University of Technology, Gothenburg, Sweden
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Tampere, Finland
| | - Yvonne Nygård
- Department of Life Sciences, Industrial Biotechnology, Chalmers University of Technology, Gothenburg, Sweden
- VTT Technical Research Centre of Finland, Espoo, Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta Campus, Tampere, Finland.
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6
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Wang H, Ishchenko A, Skudlarek J, Shen P, Dzhekieva L, Painter RE, Chen YT, Bukhtiyarova M, Leithead A, Tracy R, Babaoglu K, Bahnck-Teets C, Buevich A, Cabalu TD, Labroli M, Lange H, Lei Y, Li W, Liu J, Mann PA, Meng T, Mitchell HJ, Mulhearn J, Scapin G, Sha D, Shaw AW, Si Q, Tong L, Wu C, Wu Z, Xiao JC, Xu M, Zhang LK, McKenney D, Miller RR, Black TA, Cooke A, Balibar CJ, Klein DJ, Raheem I, Walker SS. Cerastecins inhibit membrane lipooligosaccharide transport in drug-resistant Acinetobacter baumannii. Nat Microbiol 2024; 9:1244-1255. [PMID: 38649414 DOI: 10.1038/s41564-024-01667-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/06/2024] [Indexed: 04/25/2024]
Abstract
Carbapenem-resistant Acinetobacter baumannii infections have limited treatment options. Synthesis, transport and placement of lipopolysaccharide or lipooligosaccharide (LOS) in the outer membrane of Gram-negative bacteria are important for bacterial virulence and survival. Here we describe the cerastecins, inhibitors of the A. baumannii transporter MsbA, an LOS flippase. These molecules are potent and bactericidal against A. baumannii, including clinical carbapenem-resistant Acinetobacter baumannii isolates. Using cryo-electron microscopy and biochemical analysis, we show that the cerastecins adopt a serpentine configuration in the central vault of the MsbA dimer, stalling the enzyme and uncoupling ATP hydrolysis from substrate flipping. A derivative with optimized potency and pharmacokinetic properties showed efficacy in murine models of bloodstream or pulmonary A. baumannii infection. While resistance development is inevitable, targeting a clinically unexploited mechanism avoids existing antibiotic resistance mechanisms. Although clinical validation of LOS transport remains undetermined, the cerastecins may open a path to narrow-spectrum treatment modalities for important nosocomial infections.
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Affiliation(s)
- Hao Wang
- Merck & Co., Inc., West Point, PA, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Ying Lei
- Merck & Co., Inc., West Point, PA, USA
| | - Wei Li
- Merck & Co., Inc., West Point, PA, USA
| | - Jian Liu
- Merck & Co., Inc., West Point, PA, USA
| | | | - Tao Meng
- Merck & Co., Inc., Rahway, NJ, USA
| | | | | | | | - Deyou Sha
- Merck & Co., Inc., West Point, PA, USA
| | | | - Qian Si
- Merck & Co., Inc., West Point, PA, USA
| | - Ling Tong
- Merck & Co., Inc., West Point, PA, USA
| | | | - Zhe Wu
- Merck & Co., Inc., West Point, PA, USA
| | | | - Min Xu
- Merck & Co., Inc., West Point, PA, USA
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7
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Zampaloni C, Mattei P, Bleicher K, Winther L, Thäte C, Bucher C, Adam JM, Alanine A, Amrein KE, Baidin V, Bieniossek C, Bissantz C, Boess F, Cantrill C, Clairfeuille T, Dey F, Di Giorgio P, du Castel P, Dylus D, Dzygiel P, Felici A, García-Alcalde F, Haldimann A, Leipner M, Leyn S, Louvel S, Misson P, Osterman A, Pahil K, Rigo S, Schäublin A, Scharf S, Schmitz P, Stoll T, Trauner A, Zoffmann S, Kahne D, Young JAT, Lobritz MA, Bradley KA. A novel antibiotic class targeting the lipopolysaccharide transporter. Nature 2024; 625:566-571. [PMID: 38172634 PMCID: PMC10794144 DOI: 10.1038/s41586-023-06873-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 11/16/2023] [Indexed: 01/05/2024]
Abstract
Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as a major global pathogen with limited treatment options1. No new antibiotic chemical class with activity against A. baumannii has reached patients in over 50 years1. Here we report the identification and optimization of tethered macrocyclic peptide (MCP) antibiotics with potent antibacterial activity against CRAB. The mechanism of action of this molecule class involves blocking the transport of bacterial lipopolysaccharide from the inner membrane to its destination on the outer membrane, through inhibition of the LptB2FGC complex. A clinical candidate derived from the MCP class, zosurabalpin (RG6006), effectively treats highly drug-resistant contemporary isolates of CRAB both in vitro and in mouse models of infection, overcoming existing antibiotic resistance mechanisms. This chemical class represents a promising treatment paradigm for patients with invasive infections due to CRAB, for whom current treatment options are inadequate, and additionally identifies LptB2FGC as a tractable target for antimicrobial drug development.
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Affiliation(s)
- Claudia Zampaloni
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Patrizio Mattei
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Konrad Bleicher
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- SixPeaks Bio, Basel, Switzerland
| | - Lotte Winther
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Claudia Thäte
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- Preclinical Sciences and Translational Safety, Janssen Pharmaceutica, Beerse, Belgium
| | - Christian Bucher
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Jean-Michel Adam
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- AutoChem R&D, Mettler-Toledo International, Greifensee, Switzerland
| | - Alexander Alanine
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- Independent consultant, Cambridge, Great Britain
| | - Kurt E Amrein
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Vadim Baidin
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Christoph Bieniossek
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Caterina Bissantz
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Franziska Boess
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Carina Cantrill
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Thomas Clairfeuille
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Fabian Dey
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Patrick Di Giorgio
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Pauline du Castel
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - David Dylus
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Pawel Dzygiel
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Antonio Felici
- Discovery Microbiology, Aptuit (Verona) Srl, an Evotec Company, Verona, Italy
| | - Fernando García-Alcalde
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Andreas Haldimann
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Matthew Leipner
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Semen Leyn
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Séverine Louvel
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Pauline Misson
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Andrei Osterman
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Karanbir Pahil
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Sébastien Rigo
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Adrian Schäublin
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- SixPeaks Bio, Basel, Switzerland
| | - Sebastian Scharf
- Roche Pharma Research and Early Development, Informatics, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Petra Schmitz
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Theodor Stoll
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Andrej Trauner
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Sannah Zoffmann
- Roche Pharma Research and Early Development, Therapeutic Modalities, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
- Therapeutics Discovery, Janssen Pharmaceutica, Beerse, Belgium
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - John A T Young
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Michael A Lobritz
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland.
| | - Kenneth A Bradley
- Roche Pharma Research and Early Development, Immunology, Infectious Disease and Ophthalmology, Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland.
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8
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Pahil KS, Gilman MSA, Baidin V, Clairfeuille T, Mattei P, Bieniossek C, Dey F, Muri D, Baettig R, Lobritz M, Bradley K, Kruse AC, Kahne D. A new antibiotic traps lipopolysaccharide in its intermembrane transporter. Nature 2024; 625:572-577. [PMID: 38172635 PMCID: PMC10794137 DOI: 10.1038/s41586-023-06799-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 10/30/2023] [Indexed: 01/05/2024]
Abstract
Gram-negative bacteria are extraordinarily difficult to kill because their cytoplasmic membrane is surrounded by an outer membrane that blocks the entry of most antibiotics. The impenetrable nature of the outer membrane is due to the presence of a large, amphipathic glycolipid called lipopolysaccharide (LPS) in its outer leaflet1. Assembly of the outer membrane requires transport of LPS across a protein bridge that spans from the cytoplasmic membrane to the cell surface. Maintaining outer membrane integrity is essential for bacterial cell viability, and its disruption can increase susceptibility to other antibiotics2-6. Thus, inhibitors of the seven lipopolysaccharide transport (Lpt) proteins that form this transenvelope transporter have long been sought. A new class of antibiotics that targets the LPS transport machine in Acinetobacter was recently identified. Here, using structural, biochemical and genetic approaches, we show that these antibiotics trap a substrate-bound conformation of the LPS transporter that stalls this machine. The inhibitors accomplish this by recognizing a composite binding site made up of both the Lpt transporter and its LPS substrate. Collectively, our findings identify an unusual mechanism of lipid transport inhibition, reveal a druggable conformation of the Lpt transporter and provide the foundation for extending this class of antibiotics to other Gram-negative pathogens.
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Affiliation(s)
- Karanbir S Pahil
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Morgan S A Gilman
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Vadim Baidin
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Thomas Clairfeuille
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Patrizio Mattei
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Christoph Bieniossek
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Fabian Dey
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Dieter Muri
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Remo Baettig
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Michael Lobritz
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Kenneth Bradley
- Departments of Immunology, Infectious Disease and Ophthalmology (I2O), Medicinal Chemistry and Lead Discovery, Roche Pharma Research and Early Development, Roche Innovation Center Basel, Basel, Switzerland
| | - Andrew C Kruse
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
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9
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Bailey J, Gallagher L, Manoil C. Genome-scale analysis of essential gene knockout mutants to identify an antibiotic target process. Antimicrob Agents Chemother 2023; 67:e0110223. [PMID: 37966228 PMCID: PMC10720506 DOI: 10.1128/aac.01102-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 09/22/2023] [Indexed: 11/16/2023] Open
Abstract
We describe a genome-scale approach to identify the essential biological process targeted by a new antibiotic. The procedure is based on the identification of essential genes whose inactivation sensitizes a Gram-negative bacterium (Acinetobacter baylyi) to a drug and employs recently developed transposon mutant screening and single-mutant validation procedures. The approach, based on measuring the rates of loss of newly generated knockout mutants in the presence of antibiotic, provides an alternative to traditional procedures for studying essential functions using conditional expression or activity alleles. As a proof of principle study, we evaluated whether mutations enhancing sensitivity to the β-lactam antibiotic meropenem corresponded to the known essential target process of the antibiotic (septal peptidoglycan synthesis). We found that indeed mutations inactivating most genes needed for peptidoglycan synthesis and cell division strongly sensitized cells to meropenem. Additional classes of sensitizing mutations in essential genes were also identified, including those that inactivated capsule synthesis, DNA replication, or envelope stress response regulation. The essential capsule synthesis mutants appeared to enhance meropenem sensitivity by depleting a precursor needed for both capsule and peptidoglycan synthesis. The replication mutants may sensitize cells by impairing division. Nonessential gene mutations sensitizing cells to meropenem were also identified in the screen and largely corresponded to functions subordinately associated with the essential target process, such as in peptidoglycan recycling. Overall, these results help validate a new approach to identify the essential process targeted by an antibiotic and define the larger functional network determining sensitivity to it.
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Affiliation(s)
- J. Bailey
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - L. Gallagher
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
| | - C. Manoil
- Department of Genome Sciences, University of Washington, Seattle, Washington, USA
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10
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Bhavana VH, Hillebrand GH, Gopalakrishna KP, Rapp RA, Ratner AJ, Tettelin H, Hooven TA. A group B Streptococcus indexed transposon mutant library to accelerate genetic research on an important perinatal pathogen. Microbiol Spectr 2023; 11:e0204623. [PMID: 37933989 PMCID: PMC10714824 DOI: 10.1128/spectrum.02046-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 09/29/2023] [Indexed: 11/08/2023] Open
Abstract
IMPORTANCE Group B Streptococcus (GBS) is a significant global cause of serious infections, most of which affect pregnant women, newborns, and infants. Studying GBS genetic mutant strains is a valuable approach for learning more about how these infections are caused and is a key step toward developing more effective preventative and treatment strategies. In this resource report, we describe a newly created library of defined GBS genetic mutants, containing over 1,900 genetic variants, each with a unique disruption to its chromosome. An indexed library of this scale is unprecedented in the GBS field; it includes strains with mutations in hundreds of genes whose potential functions in human disease remain unknown. We have made this resource freely available to the broader research community through deposition in a publicly funded bacterial maintenance and distribution repository.
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Affiliation(s)
- Venkata H. Bhavana
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Gideon H. Hillebrand
- University of Pittsburgh, Graduate Program in Microbiology and Immunology, Pittsburgh, Pennsylvania, USA
| | | | - Rebekah A. Rapp
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- The Ellis School, Pittsburgh, Pennsylvania, USA
| | - Adam J. Ratner
- Department of Pediatrics, New York University, New York, New York, USA
- Department of Microbiology, New York University, New York, New York, USA
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Thomas A. Hooven
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- University of Pittsburgh, Graduate Program in Microbiology and Immunology, Pittsburgh, Pennsylvania, USA
- Richard King Mellon Institute for Pediatric Research, University of Pittsburgh Medical School, Pittsburgh, Pennsylvania, USA
- UPMC Children’s Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
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11
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Gupta R, Singh M, Pathania R. Chemical genetic approaches for the discovery of bacterial cell wall inhibitors. RSC Med Chem 2023; 14:2125-2154. [PMID: 37974958 PMCID: PMC10650376 DOI: 10.1039/d3md00143a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 08/10/2023] [Indexed: 11/19/2023] Open
Abstract
Antimicrobial resistance (AMR) in bacterial pathogens is a worldwide health issue. The innovation gap in discovering new antibiotics has remained a significant hurdle in combating the AMR problem. Currently, antibiotics target various vital components of the bacterial cell envelope, nucleic acid and protein biosynthesis machinery and metabolic pathways essential for bacterial survival. The critical role of the bacterial cell envelope in cell morphogenesis and integrity makes it an attractive drug target. While a significant number of in-clinic antibiotics target peptidoglycan biosynthesis, several components of the bacterial cell envelope have been overlooked. This review focuses on various antibacterial targets in the bacterial cell wall and the strategies employed to find their novel inhibitors. This review will further elaborate on combining forward and reverse chemical genetic approaches to discover antibacterials that target the bacterial cell envelope.
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Affiliation(s)
- Rinki Gupta
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee Roorkee - 247 667 Uttarakhand India
| | - Mangal Singh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee Roorkee - 247 667 Uttarakhand India
| | - Ranjana Pathania
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee Roorkee - 247 667 Uttarakhand India
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12
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Castille J, Thépot D, Fouchécourt S, Dalbies-Tran R, Passet B, Daniel-Carlier N, Vilotte JL, Monget P. The paralogs' enigma of germ-cell specific genes dispensable for fertility: the case of 19 oogenesin genes†. Biol Reprod 2023; 109:408-414. [PMID: 37561421 DOI: 10.1093/biolre/ioad092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/28/2023] [Accepted: 08/02/2023] [Indexed: 08/11/2023] Open
Abstract
Gene knockout experiments have shown that many genes are dispensable for a given biological function. In this review, we make an assessment of male and female germ cell-specific genes dispensable for the function of reproduction in mice, the inactivation of which does not affect fertility. In particular, we describe the deletion of a 1 Mb block containing nineteen paralogous genes of the oogenesin/Pramel family specifically expressed in female and/or male germ cells, which has no consequences in both sexes. We discuss this notion of dispensability and the experiments that need to be carried out to definitively conclude that a gene is dispensable for a function.
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Affiliation(s)
- Johan Castille
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France
| | | | | | | | - Bruno Passet
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France
| | | | - Jean-Luc Vilotte
- Université Paris-Saclay, INRAE, AgroParisTech, GABI, Jouy-en-Josas, France
| | - Philippe Monget
- PRC INRAE, CNRS, IFCE, Université de Tours, Nouzilly, France
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13
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Biggs BW, Tyo KEJ. Aromatic natural products synthesis from aromatic lignin monomers using Acinetobacter baylyi ADP1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.24.554694. [PMID: 37662333 PMCID: PMC10473687 DOI: 10.1101/2023.08.24.554694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Achieving sustainable chemical synthesis and a circular economy will require process innovation to minimize or recover existing waste streams. Valorization of lignin biomass has the ability to advance this goal. While lignin has proved a recalcitrant feedstock for upgrading, biological approaches can leverage native microbial metabolism to simplify complex and heterogeneous feedstocks to tractable starting points for biochemical upgrading. Recently, we demonstrated that one microbe with lignin relevant metabolism, Acinetobacter baylyi ADP1, is both highly engineerable and capable of undergoing rapid design-build-test-learn cycles, making it an ideal candidate for these applications. Here, we utilize these genetic traits and ADP1's native β-ketoadipate metabolism to convert mock alkali pretreated liquor lignin (APL) to two valuable natural products, vanillin-glucoside and resveratrol. En route, we create strains with up to 22 genetic modifications, including up to 8 heterologously expressed enzymes. Our approach takes advantage of preexisting aromatic species in APL (vanillate, ferulate, and p-coumarate) to create shortened biochemical routes to end products. Together, this work demonstrates ADP1's potential as a platform for upgrading lignin waste streams and highlights the potential for biosynthetic methods to maximize the existing chemical potential of lignin aromatic monomers.
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Affiliation(s)
- Bradley W. Biggs
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
| | - Keith E. J. Tyo
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
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14
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Wilkinson AJ, Ooi N, Finlayson J, Lee VE, Lyth D, Maskew KS, Newman R, Orr D, Ansell K, Birchall K, Canning P, Coombs P, Fusani L, McIver E, Pisco J, Ireland PM, Jenkins C, Norville IH, Southern SJ, Cowan R, Hall G, Kettleborough C, Savage VJ, Cooper IR. Evaluating the druggability of TrmD, a potential antibacterial target, through design and microbiological profiling of a series of potent TrmD inhibitors. Bioorg Med Chem Lett 2023; 90:129331. [PMID: 37187252 DOI: 10.1016/j.bmcl.2023.129331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/17/2023]
Abstract
The post-transcriptional modifier tRNA-(N1G37) methyltransferase (TrmD) has been proposed to be essential for growth in many Gram-negative and Gram-positive pathogens, however previously reported inhibitors show only weak antibacterial activity. In this work, optimisation of fragment hits resulted in compounds with low nanomolar TrmD inhibition incorporating features designed to enhance bacterial permeability and covering a range of physicochemical space. The resulting lack of significant antibacterial activity suggests that whilst TrmD is highly ligandable, its essentiality and druggability are called into question.
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Affiliation(s)
- Andrew J Wilkinson
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK.
| | - Nicola Ooi
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Jonathan Finlayson
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Victoria E Lee
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - David Lyth
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Kathryn S Maskew
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Rebecca Newman
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - David Orr
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Keith Ansell
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Kristian Birchall
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Peter Canning
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Peter Coombs
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Lucia Fusani
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Ed McIver
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - João Pisco
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - Philip M Ireland
- CBR division, Dstl Porton Down, Salisbury, Wiltshire, SP4 0JQ, UK
| | | | | | | | - Richard Cowan
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, LE1 7RH, UK
| | - Gareth Hall
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, LE1 7RH, UK
| | | | - Victoria J Savage
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
| | - Ian R Cooper
- Infex Therapeutics Ltd, Mereside, Alderley Park, Macclesfield, SK10 4TG, UK
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15
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Schroer WF, Kepner HE, Uchimiya M, Mejia C, Rodriguez LT, Reisch CR, Moran MA. Functional annotation and importance of marine bacterial transporters of plankton exometabolites. ISME COMMUNICATIONS 2023; 3:37. [PMID: 37185952 PMCID: PMC10130141 DOI: 10.1038/s43705-023-00244-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 04/01/2023] [Accepted: 04/14/2023] [Indexed: 05/17/2023]
Abstract
Metabolite exchange within marine microbial communities transfers carbon and other major elements through global cycles and forms the basis of microbial interactions. Yet lack of gene annotations and concern about the quality of existing ones remain major impediments to revealing currencies of carbon flux. We employed an arrayed mutant library of the marine bacterium Ruegeria pomeroyi DSS-3 to experimentally annotate substrates of organic compound transporter systems, using mutant growth and compound drawdown analyses to link transporters to their cognate substrates. Mutant experiments verified substrates for thirteen R. pomeroyi transporters. Four were previously hypothesized based on gene expression data (taurine, glucose/xylose, isethionate, and cadaverine/putrescine/spermidine); five were previously hypothesized based on homology to experimentally annotated transporters in other bacteria (citrate, glycerol, N-acetylglucosamine, fumarate/malate/succinate, and dimethylsulfoniopropionate); and four had no previous annotations (thymidine, carnitine, cysteate, and 3-hydroxybutyrate). These bring the total number of experimentally-verified organic carbon influx transporters to 18 of 126 in the R. pomeroyi genome. In a longitudinal study of a coastal phytoplankton bloom, expression patterns of the experimentally annotated transporters linked them to different stages of the bloom, and also led to the hypothesis that citrate and 3-hydroxybutyrate were among the most highly available bacterial substrates. Improved functional annotation of the gatekeepers of organic carbon uptake is critical for deciphering carbon flux and fate in microbial ecosystems.
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Affiliation(s)
- William F Schroer
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
| | - Hannah E Kepner
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Mario Uchimiya
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, 30602, USA
| | - Catalina Mejia
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA
| | | | - Christopher R Reisch
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA
| | - Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, 30602, USA.
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16
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Romano K, Hung D. Targeting LPS biosynthesis and transport in gram-negative bacteria in the era of multi-drug resistance. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119407. [PMID: 36543281 PMCID: PMC9922520 DOI: 10.1016/j.bbamcr.2022.119407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 11/09/2022] [Accepted: 11/18/2022] [Indexed: 12/23/2022]
Abstract
Gram-negative bacteria pose a major threat to human health in an era fraught with multi-drug resistant bacterial infections. Despite extensive drug discovery campaigns over the past decades, no new antibiotic target class effective against gram-negative bacteria has become available to patients since the advent of the carbapenems in 1985. Antibiotic discovery efforts against gram-negative bacteria have been hampered by limited intracellular accumulation of xenobiotics, in large part due to the impermeable cell envelope comprising lipopolysaccharide (LPS) in the outer leaflet of the outer membrane, as well as a panoply of efflux pumps. The biosynthesis and transport of LPS are essential to the viability and virulence of most gram-negative bacteria. Thus, both LPS biosynthesis and transport are attractive pathways to target therapeutically. In this review, we summarize the LPS biosynthesis and transport pathways and discuss efforts to find small molecule inhibitors against targets within these pathways.
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Affiliation(s)
- K.P. Romano
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, MA, USA,The Broad Institute of MIT and Harvard, Cambridge, MA, USA,Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA
| | - D.T. Hung
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA,Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA,Department of Genetics, Harvard Medical School, Boston, MA, USA,Corresponding author at: The Broad Institute of MIT and Harvard, Cambridge, MA, USA. (D.T. Hung)
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17
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Construction of an Ordered Transposon Library for Uropathogenic Proteus mirabilis HI4320. Microbiol Spectr 2022; 10:e0314222. [PMID: 36377916 PMCID: PMC9769666 DOI: 10.1128/spectrum.03142-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ordered transposon libraries are a valuable resource for many bacterial species, especially those with difficult methods for generating targeted genetic mutations. Here, we present the construction of an ordered transposon library for the bacterial urinary tract pathogen Proteus mirabilis strain HI4320. This library will facilitate future studies into P. mirabilis biology. For large experimental screens, it may be used to overcome bottleneck constraints and avoid biased outcomes resulting from gene length. For smaller studies, the library allows sidestepping the laborious construction of single targeted mutants. This library, containing 18,432 wells, was condensed into a smaller library containing 1,728 mutants. Each selected mutant had a single transposon insertion in an open reading frame, covering 45% of predicted genes encoded by P. mirabilis HI4320. This coverage was lower than expected and was due both to library wells with no mapped insertions and a surprisingly high proportion of mixed clones and multiple transposon insertion events. We offer recommendations for improving future library construction and suggestions for how to use this P. mirabilis library resource. IMPORTANCE Ordered libraries facilitate large genetic screens by guaranteeing high genomic coverage with a minimal number of mutants, and they can save time and effort by reducing the need to construct targeted mutations. This resource is now available for P. mirabilis, a common and complicating agent of catheter-associated urinary tract infection. We also present obstacles encountered during library construction with the goal to aid others who would like to construct ordered transposon libraries in other species.
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18
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Parisutham V, Chhabra S, Ali MZ, Brewster RC. Tunable transcription factor library for robust quantification of regulatory properties in Escherichia coli. Mol Syst Biol 2022; 18:e10843. [PMID: 35694815 PMCID: PMC9189660 DOI: 10.15252/msb.202110843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 11/12/2022] Open
Abstract
Predicting the quantitative regulatory function of transcription factors (TFs) based on factors such as binding sequence, binding location, and promoter type is not possible. The interconnected nature of gene networks and the difficulty in tuning individual TF concentrations make the isolated study of TF function challenging. Here, we present a library of Escherichia coli strains designed to allow for precise control of the concentration of individual TFs enabling the study of the role of TF concentration on physiology and regulation. We demonstrate the usefulness of this resource by measuring the regulatory function of the zinc‐responsive TF, ZntR, and the paralogous TF pair, GalR/GalS. For ZntR, we find that zinc alters ZntR regulatory function in a way that enables activation of the regulated gene to be robust with respect to ZntR concentration. For GalR and GalS, we are able to demonstrate that these paralogous TFs have fundamentally distinct regulatory roles beyond differences in binding affinity.
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Affiliation(s)
- Vinuselvi Parisutham
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Shivani Chhabra
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Md Zulfikar Ali
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Robert C Brewster
- Department of Systems Biology, University of Massachusetts Chan Medical School, Worcester, MA, USA.,Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, MA, USA
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19
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Perchat N, Dubois C, Mor-Gautier R, Duquesne S, Lechaplais C, Roche D, Fouteau S, Darii E, Perret A. Characterization of a novel β-alanine biosynthetic pathway consisting of promiscuous metabolic enzymes. J Biol Chem 2022; 298:102067. [PMID: 35623386 PMCID: PMC9213253 DOI: 10.1016/j.jbc.2022.102067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/19/2022] [Accepted: 05/22/2022] [Indexed: 10/28/2022] Open
Abstract
Bacteria adapt to utilize the nutrients available in their environment through a sophisticated metabolic system composed of highly specialized enzymes. Although these enzymes can metabolize molecules other than those for which they evolved, their efficiency toward promiscuous substrates is considered too low to be of physiological relevance. Herein, we investigated the possibility that these promiscuous enzymes are actually efficient enough at metabolizing secondary substrates to modify the phenotype of the cell. For example, in the bacterium Acinetobacter baylyi ADP1 (ADP1), panD (coding for l-aspartate decarboxylase) encodes the only protein known to catalyze the synthesis of β-alanine, an obligate intermediate in CoA synthesis. However, we show that the ADP1 ΔpanD mutant could also form this molecule through an unknown metabolic pathway arising from promiscuous enzymes and grow as efficiently as the wildtype strain. Using metabolomic analyses, we identified 1,3-diaminopropane and 3-aminopropanal as intermediates in this novel pathway. We also conducted activity screening and enzyme kinetics to elucidate candidate enzymes involved in this pathway, including 2,4-diaminobutyrate aminotransferase (Dat) and 2,4-diaminobutyrate decarboxylase (Ddc) and validated this pathway in vivo by analyzing the phenotype of mutant bacterial strains. Finally, we experimentally demonstrate that this novel metabolic route is not restricted to ADP1. We propose that the occurrence of conserved genes in hundreds of genomes across many phyla suggests that this previously undescribed pathway is widespread in prokaryotes.
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Affiliation(s)
- Nadia Perchat
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Christelle Dubois
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Rémi Mor-Gautier
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Sophie Duquesne
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Christophe Lechaplais
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - David Roche
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Stéphanie Fouteau
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Ekaterina Darii
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France
| | - Alain Perret
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, Evry, France.
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20
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Hubloher JJ, van der Sande L, Müller V. Na + homeostasis in Acinetobacter baumannii is facilitated via the activity of the Mrp antiporter. Environ Microbiol 2022; 24:4411-4424. [PMID: 35535800 DOI: 10.1111/1462-2920.16039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/26/2022] [Accepted: 05/04/2022] [Indexed: 11/30/2022]
Abstract
The human opportunistic pathogen Acinetobacter baumannii is a global threat to healthcare institutions worldwide, since it developed very efficient strategies to evade host defense and to adapt to the different environmental conditions of the host. This worked focused on the importance of Na+ homeostasis in A. baumannii with regards to pathobiological aspects. In silico studies revealed a homologue of a multicomponent Na+ /H+ antiporter system. Inactivation of the Mrp antiporter through deletion of the first gene (mrpA') resulted in a mutant that was sensitive to increasing pH values. Furthermore, the strain was highly sensitive to increasing Na+ and Li+ concentrations. Increasing Na+ sensitivity is thought to be responsible for growth impairment in human fluids. Furthermore, deletion of mrpA' is associated with energetic defects, inhibition of motility and survival under anoxic and dry conditions.
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Affiliation(s)
- Josephine Joy Hubloher
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
| | - Lisa van der Sande
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
| | - Volker Müller
- Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
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21
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Hogan AM, Cardona ST. Gradients in gene essentiality reshape antibacterial research. FEMS Microbiol Rev 2022; 46:fuac005. [PMID: 35104846 PMCID: PMC9075587 DOI: 10.1093/femsre/fuac005] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 01/14/2022] [Accepted: 01/24/2022] [Indexed: 02/03/2023] Open
Abstract
Essential genes encode the processes that are necessary for life. Until recently, commonly applied binary classifications left no space between essential and non-essential genes. In this review, we frame bacterial gene essentiality in the context of genetic networks. We explore how the quantitative properties of gene essentiality are influenced by the nature of the encoded process, environmental conditions and genetic background, including a strain's distinct evolutionary history. The covered topics have important consequences for antibacterials, which inhibit essential processes. We argue that the quantitative properties of essentiality can thus be used to prioritize antibacterial cellular targets and desired spectrum of activity in specific infection settings. We summarize our points with a case study on the core essential genome of the cystic fibrosis pathobiome and highlight avenues for targeted antibacterial development.
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Affiliation(s)
- Andrew M Hogan
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
| | - Silvia T Cardona
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
- Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, University of Manitoba, Room 543 - 745 Bannatyne Avenue, Winnipeg, Manitoba, R3E 0J9, Canada
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22
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Targeting the ATP synthase in bacterial and fungal pathogens – beyond Mycobacterium tuberculosis. J Glob Antimicrob Resist 2022; 29:29-41. [DOI: 10.1016/j.jgar.2022.01.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/24/2022] [Accepted: 01/30/2022] [Indexed: 11/23/2022] Open
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23
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Characterization of highly ferulate-tolerant Acinetobacter baylyi ADP1 isolates by a rapid reverse-engineering method. Appl Environ Microbiol 2021; 88:e0178021. [PMID: 34788063 DOI: 10.1128/aem.01780-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Adaptive laboratory evolution (ALE) is a powerful approach for improving phenotypes of microbial hosts. Evolved strains typically contain numerous mutations that can be revealed by whole-genome sequencing. However, determining the contribution of specific mutations to new phenotypes is typically challenging and laborious. This task is complicated by factors such as the mutation type, the genomic context, and the interplay between different mutations. Here, a novel approach was developed to identify the significance of mutations in strains evolved from Acinetobacter baylyi ADP1. This method, termed Rapid Advantageous Mutation ScrEening and Selection (RAMSES), was used to analyze mutants that emerged from stepwise adaptation to, and consumption of, high levels of ferulate, a common lignin-derived aromatic compound. After whole-genome sequence analysis, RAMSES allowed rapid determination of effective mutations and seamless introduction of the beneficial mutations into the chromosomes of new strains with different genetic backgrounds. This simple approach to reverse-engineering exploits the natural competence and high recombination efficiency of ADP1. Mutated DNA, added directly to growing cells, replaces homologous chromosomal regions to generate transformants that will become enriched if there is selective benefit. Thus, advantageous mutations can be rapidly identified. Here, the growth advantage of transformants under selective pressure revealed key mutations in genes related to aromatic transport, including hcaE, hcaK, and vanK, and a gene, ACIAD0482, which is associated with lipopolysaccharide synthesis. This study provides insights into enhanced utilization of industrially relevant aromatic substrates and demonstrates the use of A. baylyi ADP1 as a convenient platform for strain development and evolution studies. Importance Microbial conversion of lignin-enriched streams is a promising approach for lignin valorization. However, the lignin-derived aromatic compounds are toxic to cells at relevant concentrations. Although adaptive laboratory evolution (ALE) is a powerful approach to develop more tolerant strains, it is typically laborious to identify the mechanisms underlying phenotypic improvement. We employed Acinetobacter baylyi ADP1, an aromatic compound degrading strain that may be useful for biotechnology. The natural competence and high recombination efficiency of this strain can be exploited for critical applications such as the breakdown of lignin and plastics, abundant polymers composed of aromatic subunits. The natural transformability of this bacterium enabled us to develop a novel approach for rapid screening of advantageous mutations from ALE-derived aromatic-tolerant ADP1-derived strains. We clarified the mechanisms and genetic targets for improved tolerance towards common lignin-derived aromatic compounds. This study facilitates metabolic engineering for lignin valorization.
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Campos TL, Korhonen PK, Hofmann A, Gasser RB, Young ND. Harnessing model organism genomics to underpin the machine learning-based prediction of essential genes in eukaryotes - Biotechnological implications. Biotechnol Adv 2021; 54:107822. [PMID: 34461202 DOI: 10.1016/j.biotechadv.2021.107822] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/17/2021] [Accepted: 08/24/2021] [Indexed: 12/17/2022]
Abstract
The availability of high-quality genomes and advances in functional genomics have enabled large-scale studies of essential genes in model eukaryotes, including the 'elegant worm' (Caenorhabditis elegans; Nematoda) and the 'vinegar fly' (Drosophila melanogaster; Arthropoda). However, this is not the case for other, much less-studied organisms, such as socioeconomically important parasites, for which functional genomic platforms usually do not exist. Thus, there is a need to develop innovative techniques or approaches for the prediction, identification and investigation of essential genes. A key approach that could enable the prediction of such genes is machine learning (ML). Here, we undertake an historical review of experimental and computational approaches employed for the characterisation of essential genes in eukaryotes, with a particular focus on model ecdysozoans (C. elegans and D. melanogaster), and discuss the possible applicability of ML-approaches to organisms such as socioeconomically important parasites. We highlight some recent results showing that high-performance ML, combined with feature engineering, allows a reliable prediction of essential genes from extensive, publicly available 'omic data sets, with major potential to prioritise such genes (with statistical confidence) for subsequent functional genomic validation. These findings could 'open the door' to fundamental and applied research areas. Evidence of some commonality in the essential gene-complement between these two organisms indicates that an ML-engineering approach could find broader applicability to ecdysozoans such as parasitic nematodes or arthropods, provided that suitably large and informative data sets become/are available for proper feature engineering, and for the robust training and validation of algorithms. This area warrants detailed exploration to, for example, facilitate the identification and characterisation of essential molecules as novel targets for drugs and vaccines against parasitic diseases. This focus is particularly important, given the substantial impact that such diseases have worldwide, and the current challenges associated with their prevention and control and with drug resistance in parasite populations.
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Affiliation(s)
- Tulio L Campos
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia; Bioinformatics Core Facility, Instituto Aggeu Magalhães, Fundação Oswaldo Cruz (IAM-Fiocruz), Recife, Pernambuco, Brazil
| | - Pasi K Korhonen
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Andreas Hofmann
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Robin B Gasser
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Neil D Young
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria 3010, Australia.
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25
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Rapid ordering of barcoded transposon insertion libraries of anaerobic bacteria. Nat Protoc 2021; 16:3049-3071. [PMID: 34021295 DOI: 10.1038/s41596-021-00531-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 02/16/2021] [Indexed: 02/07/2023]
Abstract
Commensal bacteria from the human intestinal microbiota play important roles in health and disease. Research into the mechanisms by which these bacteria exert their effects is hampered by the complexity of the microbiota, the strict growth requirements of the individual species and a lack of genetic tools and resources. The assembly of ordered transposon insertion libraries, in which nearly all nonessential genes have been disrupted and the strains stored as independent monocultures, would be a transformative resource for research into many microbiota members. However, assembly of these libraries must be fast and inexpensive in order to empower investigation of the large number of species that typically compose gut communities. The methods used to generate ordered libraries must also be adapted to the anaerobic growth requirements of most intestinal bacteria. We have developed a protocol to assemble ordered libraries of transposon insertion mutants that is fast, cheap and effective for even strict anaerobes. The protocol differs from currently available methods by making use of cell sorting to order the library and barcoded transposons to facilitate the localization of ordered mutations in the library. By tracking transposon insertions using barcode sequencing, our approach increases the accuracy and reduces the time and effort required to locate mutants in the library. Ordered libraries can be sorted and characterized over the course of 2 weeks using this approach. We expect this protocol will lower the barrier to generating comprehensive, ordered mutant libraries for many species in the human microbiota, allowing for new investigations into genotype-phenotype relationships within this important microbial ecosystem.
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26
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Kobras CM, Fenton AK, Sheppard SK. Next-generation microbiology: from comparative genomics to gene function. Genome Biol 2021; 22:123. [PMID: 33926534 PMCID: PMC8082670 DOI: 10.1186/s13059-021-02344-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 04/08/2021] [Indexed: 11/12/2022] Open
Abstract
Microbiology is at a turning point in its 120-year history. Widespread next-generation sequencing has revealed genetic complexity among bacteria that could hardly have been imagined by pioneers such as Pasteur, Escherich and Koch. This data cascade brings enormous potential to improve our understanding of individual bacterial cells and the genetic basis of phenotype variation. However, this revolution in data science cannot replace established microbiology practices, presenting the challenge of how to integrate these new techniques. Contrasting comparative and functional genomic approaches, we evoke molecular microbiology theory and established practice to present a conceptual framework and practical roadmap for next-generation microbiology.
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Affiliation(s)
- Carolin M Kobras
- Department of Molecular Biology & Biotechnology, University of Sheffield, The Florey Institute for Host-Pathogen Interactions, Sheffield, UK
| | - Andrew K Fenton
- Department of Molecular Biology & Biotechnology, University of Sheffield, The Florey Institute for Host-Pathogen Interactions, Sheffield, UK.
| | - Samuel K Sheppard
- Department of Biology & Biochemistry, University of Bath, Milner Centre for Evolution, Bath, UK.
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27
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Acinetobacter baylyi ADP1-naturally competent for synthetic biology. Essays Biochem 2021; 65:309-318. [PMID: 33769448 DOI: 10.1042/ebc20200136] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 02/02/2023]
Abstract
Acinetobacter baylyi ADP1 is a non-pathogenic soil bacterium known for its metabolic diversity and high natural transformation and recombination efficiency. For these features, A. baylyi ADP1 has been long exploited in studying bacterial genetics and metabolism. The large pool of information generated in the fundamental studies has facilitated the development of a broad range of sophisticated and robust tools for the genome and metabolic engineering of ADP1. This mini-review outlines and describes the recent advances in ADP1 engineering and tool development, exploited in, for example, pathway and enzyme evolution, genome reduction and stabilization, and for the production of native and non-native products in both pure and rationally designed multispecies cultures. The rapidly expanding toolbox together with the unique features of A. baylyi ADP1 provide a strong base for a microbial cell factory excelling in synthetic biology applications where evolution meets rational engineering.
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28
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Elucidating Essential Genes in Plant-Associated Pseudomonas protegens Pf-5 Using Transposon Insertion Sequencing. J Bacteriol 2021; 203:JB.00432-20. [PMID: 33257523 DOI: 10.1128/jb.00432-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 11/18/2020] [Indexed: 12/30/2022] Open
Abstract
Gene essentiality studies have been performed on numerous bacterial pathogens, but essential gene sets have been determined for only a few plant-associated bacteria. Pseudomonas protegens Pf-5 is a plant-commensal, biocontrol bacterium that can control disease-causing pathogens on a wide range of crops. Work on Pf-5 has mostly focused on secondary metabolism and biocontrol genes, but genome-wide approaches such as high-throughput transposon mutagenesis have not yet been used for this species. In this study, we generated a dense P. protegens Pf-5 transposon mutant library and used transposon-directed insertion site sequencing (TraDIS) to identify 446 genes essential for growth on rich media. Genes required for fundamental cellular machinery were enriched in the essential gene set, while genes related to nutrient biosynthesis, stress responses, and transport were underrepresented. The majority of Pf-5 essential genes were part of the P. protegens core genome. Comparison of the essential gene set of Pf-5 with those of two plant-associated pseudomonads, P. simiae and P. syringae, and the well-studied opportunistic human pathogen P. aeruginosa PA14 showed that the four species share a large number of essential genes, but each species also had uniquely essential genes. Comparison of the Pf-5 in silico-predicted and in vitro-determined essential gene sets highlighted the essential cellular functions that are over- and underestimated by each method. Expanding essentiality studies into bacteria with a range of lifestyles may improve our understanding of the biological processes important for bacterial survival and growth.IMPORTANCE Essential genes are those crucial for survival or normal growth rates in an organism. Essential gene sets have been identified in numerous bacterial pathogens but only a few plant-associated bacteria. Employing genome-wide approaches, such as transposon insertion sequencing, allows for the concurrent analyses of all genes of a bacterial species and rapid determination of essential gene sets. We have used transposon insertion sequencing to systematically analyze thousands of Pseudomonas protegens Pf-5 genes and gain insights into gene functions and interactions that are not readily available using traditional methods. Comparing Pf-5 essential genes with those of three other pseudomonads highlights how gene essentiality varies between closely related species.
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29
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Judd JA, Canestrari J, Clark R, Joseph A, Lapierre P, Lasek-Nesselquist E, Mir M, Palumbo M, Smith C, Stone M, Upadhyay A, Wirth SE, Dedrick RM, Meier CG, Russell DA, Dills A, Dove E, Kester J, Wolf ID, Zhu J, Rubin ER, Fortune S, Hatfull GF, Gray TA, Wade JT, Derbyshire KM. A Mycobacterial Systems Resource for the Research Community. mBio 2021; 12:e02401-20. [PMID: 33653882 PMCID: PMC8092266 DOI: 10.1128/mbio.02401-20] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Functional characterization of bacterial proteins lags far behind the identification of new protein families. This is especially true for bacterial species that are more difficult to grow and genetically manipulate than model systems such as Escherichia coli and Bacillus subtilis To facilitate functional characterization of mycobacterial proteins, we have established a Mycobacterial Systems Resource (MSR) using the model organism Mycobacterium smegmatis This resource focuses specifically on 1,153 highly conserved core genes that are common to many mycobacterial species, including Mycobacterium tuberculosis, in order to provide the most relevant information and resources for the mycobacterial research community. The MSR includes both biological and bioinformatic resources. The biological resource includes (i) an expression plasmid library of 1,116 genes fused to a fluorescent protein for determining protein localization; (ii) a library of 569 precise deletions of nonessential genes; and (iii) a set of 843 CRISPR-interference (CRISPRi) plasmids specifically targeted to silence expression of essential core genes and genes for which a precise deletion was not obtained. The bioinformatic resource includes information about individual genes and a detailed assessment of protein localization. We anticipate that integration of these initial functional analyses and the availability of the biological resource will facilitate studies of these core proteins in many Mycobacterium species, including the less experimentally tractable pathogens M. abscessus, M. avium, M. kansasii, M. leprae, M. marinum, M. tuberculosis, and M. ulceransIMPORTANCE Diseases caused by mycobacterial species result in millions of deaths per year globally, and present a substantial health and economic burden, especially in immunocompromised patients. Difficulties inherent in working with mycobacterial pathogens have hampered the development and application of high-throughput genetics that can inform genome annotations and subsequent functional assays. To facilitate mycobacterial research, we have created a biological and bioinformatic resource (https://msrdb.org/) using Mycobacterium smegmatis as a model organism. The resource focuses specifically on 1,153 proteins that are highly conserved across the mycobacterial genus and, therefore, likely perform conserved mycobacterial core functions. Thus, functional insights from the MSR will apply to all mycobacterial species. We believe that the availability of this mycobacterial systems resource will accelerate research throughout the mycobacterial research community.
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Affiliation(s)
- J A Judd
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - J Canestrari
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - R Clark
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - A Joseph
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - P Lapierre
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - E Lasek-Nesselquist
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - M Mir
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - M Palumbo
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - C Smith
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - M Stone
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - A Upadhyay
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - S E Wirth
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
| | - R M Dedrick
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - C G Meier
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - D A Russell
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - A Dills
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - E Dove
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - J Kester
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - I D Wolf
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - J Zhu
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - E R Rubin
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - S Fortune
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - G F Hatfull
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - T A Gray
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
| | - J T Wade
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
| | - K M Derbyshire
- Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Biomedical Sciences, University at Albany, Albany, New York, USA
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30
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Han X, Guo J, Pang E, Song H, Lin K. Ab Initio Construction and Evolutionary Analysis of Protein-Coding Gene Families with Partially Homologous Relationships: Closely Related Drosophila Genomes as a Case Study. Genome Biol Evol 2021; 12:185-202. [PMID: 32108239 PMCID: PMC7144356 DOI: 10.1093/gbe/evaa041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2020] [Indexed: 01/05/2023] Open
Abstract
How have genes evolved within a well-known genome phylogeny? Many protein-coding genes should have evolved as a whole at the gene level, and some should have evolved partly through fragments at the subgene level. To comprehensively explore such complex homologous relationships and better understand gene family evolution, here, with de novo-identified modules, the subgene units which could consecutively cover proteins within a set of closely related species, we applied a new phylogeny-based approach that considers evolutionary models with partial homology to classify all protein-coding genes in nine Drosophila genomes. Compared with two other popular methods for gene family construction, our approach improved practical gene family classifications with a more reasonable view of homology and provided a much more complete landscape of gene family evolution at the gene and subgene levels. In the case study, we found that most expanded gene families might have evolved mainly through module rearrangements rather than gene duplications and mainly generated single-module genes through partial gene duplication, suggesting that there might be pervasive subgene rearrangement in the evolution of protein-coding gene families. The use of a phylogeny-based approach with partial homology to classify and analyze protein-coding gene families may provide us with a more comprehensive landscape depicting how genes evolve within a well-known genome phylogeny.
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Affiliation(s)
- Xia Han
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, China
| | - Jindan Guo
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, China
| | - Erli Pang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, China
| | - Hongtao Song
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, China
| | - Kui Lin
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, China
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31
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Price MN, Deutschbauer AM, Arkin AP. Four families of folate-independent methionine synthases. PLoS Genet 2021; 17:e1009342. [PMID: 33534785 PMCID: PMC7857596 DOI: 10.1371/journal.pgen.1009342] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/05/2021] [Indexed: 11/29/2022] Open
Abstract
Although most organisms synthesize methionine from homocysteine and methyl folates, some have “core” methionine synthases that lack folate-binding domains and use other methyl donors. In vitro, the characterized core synthases use methylcobalamin as a methyl donor, but in vivo, they probably rely on corrinoid (vitamin B12-binding) proteins. We identified four families of core methionine synthases that are distantly related to each other (under 30% pairwise amino acid identity). From the characterized enzymes, we identified the families MesA, which is found in methanogens, and MesB, which is found in anaerobic bacteria and archaea with the Wood-Ljungdahl pathway. A third uncharacterized family, MesC, is found in anaerobic archaea that have the Wood-Ljungdahl pathway and lack known forms of methionine synthase. We predict that most members of the MesB and MesC families accept methyl groups from the iron-sulfur corrinoid protein of that pathway. The fourth family, MesD, is found only in aerobic bacteria. Using transposon mutants and complementation, we show that MesD does not require 5-methyltetrahydrofolate or cobalamin. Instead, MesD requires an uncharacterized protein family (DUF1852) and oxygen for activity. Methionine is one of the amino acids that make up proteins, and the final step in methionine synthesis is the transfer of a methyl group. In most organisms, the methyl group is obtained from methyl folates, but some anaerobic bacteria and archaea are thought to use corrinoid (vitamin B12-binding) proteins instead. By analyzing the sequences of the potential methionine synthases across the genomes of diverse bacteria and archaea, we identified four families of folate-independent methionine synthases. For three of these families, we can use co-occurrence with corrinoid proteins to predict their likely partners. We show that the fourth family does not require vitamin B12; instead, it obtains methyl groups from an oxygen-dependent partner protein. Our results will help us understand the growth requirements of diverse bacteria and archaea.
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Affiliation(s)
- Morgan N. Price
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Lab, Berkeley, California, United States of America
- * E-mail: (MNP); (APA)
| | - Adam M. Deutschbauer
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Lab, Berkeley, California, United States of America
| | - Adam P. Arkin
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Lab, Berkeley, California, United States of America
- Department of Bioengineering, University of California, Berkeley, California, United States of America
- * E-mail: (MNP); (APA)
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32
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Luo H, Lin Y, Liu T, Lai FL, Zhang CT, Gao F, Zhang R. DEG 15, an update of the Database of Essential Genes that includes built-in analysis tools. Nucleic Acids Res 2021; 49:D677-D686. [PMID: 33095861 PMCID: PMC7779065 DOI: 10.1093/nar/gkaa917] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 09/30/2020] [Accepted: 10/06/2020] [Indexed: 12/21/2022] Open
Abstract
Essential genes refer to genes that are required by an organism to survive under specific conditions. Studies of the minimal-gene-set for bacteria have elucidated fundamental cellular processes that sustain life. The past five years have seen a significant progress in identifying human essential genes, primarily due to the successful use of CRISPR/Cas9 in various types of human cells. DEG 15, a new release of the Database of Essential Genes (www.essentialgene.org), has provided major advancements, compared to DEG 10. Specifically, the number of eukaryotic essential genes has increased by more than fourfold, and that of prokaryotic ones has more than doubled. Of note, the human essential-gene number has increased by more than tenfold. Moreover, we have developed built-in analysis modules by which users can perform various analyses, such as essential-gene distributions between bacterial leading and lagging strands, sub-cellular localization distribution, enrichment analysis of gene ontology and KEGG pathways, and generation of Venn diagrams to compare and contrast gene sets between experiments. Additionally, the database offers customizable BLAST tools for performing species- and experiment-specific BLAST searches. Therefore, DEG comprehensively harbors updated human-curated essential-gene records among prokaryotes and eukaryotes with built-in tools to enhance essential-gene analysis.
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Affiliation(s)
- Hao Luo
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Yan Lin
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Tao Liu
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Fei-Liao Lai
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Chun-Ting Zhang
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China
| | - Feng Gao
- Department of Physics, School of Science, Tianjin University, Tianjin 300072, China.,Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin University, Tianjin 300072, China
| | - Ren Zhang
- Center for Molecular Medicine and Genetics, School of Medicine, Wayne State University, Detroit, MI 48201, USA
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33
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Jiang X, Palazzotto E, Wybraniec E, Munro LJ, Zhang H, Kell DB, Weber T, Lee SY. Automating Cloning by Natural Transformation. ACS Synth Biol 2020; 9:3228-3235. [PMID: 33231069 DOI: 10.1021/acssynbio.0c00240] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Affordable and automated cloning platforms are essential to many synthetic biology studies. However, the traditional E. coli-based cloning is a major bottleneck as it requires heat shock or electroporation implemented in the robotic workflows. To overcome this problem, we explored bacterial natural transformation for automatic DNA cloning and engineering. Recombinant plasmids are efficiently generated from Gibson or overlap extension PCR (OE-PCR) products by simply adding the DNA into Acinetobacter baylyi ADP1 cultures. No DNA purification, competence induction, or special equipment is required. Up to 10,000 colonies were obtained per microgram of DNA, while the number of false positive colonies was low. We cloned and engineered 21 biosynthetic gene clusters (BGCs) of various types, with length from 1.5 to 19 kb and GC content from 35% to 72%. One of them, a nucleoside BGC, showed antibacterial activity. Furthermore, the method was easily transferred to a low-cost benchtop robot with consistent cloning efficiency. Thus, this automatic natural transformation (ANT) cloning provides an easy, robust, and affordable platform for high throughput DNA engineering.
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Affiliation(s)
- Xinglin Jiang
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Emilia Palazzotto
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Ewa Wybraniec
- Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Lachlan Jake Munro
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Haibo Zhang
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, P. R. China
| | - Douglas B. Kell
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
- Department of Biochemistry and Systems Biology,Institute of Systems, Molecular and Integrative Biology, Biosciences Building, University of Liverpool, LiverpoolL69 7ZB, UK
| | - Tilmann Weber
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Sang Yup Lee
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
- Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Plus Program), Center for Systems and Synthetic Biotechnology, Institute for the BioCentury, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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Kloos J, Johnsen PJ, Harms K. Tn 1 transposition in the course of natural transformation enables horizontal antibiotic resistance spread in Acinetobacter baylyi. MICROBIOLOGY-SGM 2020; 167. [PMID: 33270000 PMCID: PMC8116780 DOI: 10.1099/mic.0.001003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Transposons are genetic elements that change their intracellular genomic position by transposition and are spread horizontally between bacteria when located on plasmids. It was recently discovered that transposition from fully heterologous DNA also occurs in the course of natural transformation. Here, we characterize the molecular details and constraints of this process using the replicative transposon Tn1 and the naturally competent bacterium Acinetobacter baylyi. We find that chromosomal insertion of Tn1 by transposition occurs at low but detectable frequencies and preferably around the A. baylyi terminus of replication. We show that Tn1 transposition is facilitated by transient expression of the transposase and resolvase encoded by the donor DNA. RecA protein is essential for the formation of a circular, double-stranded cytoplasmic intermediate from incoming donor DNA, and RecO is beneficial but not essential in this process. Absence of the recipient RecBCD nuclease stabilizes the double-stranded intermediate. Based on these results, we suggest a mechanistic model for transposition during natural transformation.
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Affiliation(s)
- Julia Kloos
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Pål J Johnsen
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Klaus Harms
- Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
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CsrA Supports both Environmental Persistence and Host-Associated Growth of Acinetobacter baumannii. Infect Immun 2020; 88:IAI.00259-20. [PMID: 32989034 DOI: 10.1128/iai.00259-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 09/18/2020] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii is an opportunistic and frequently multidrug-resistant Gram-negative bacterial pathogen that primarily infects critically ill individuals. Indirect transmission from patient to patient in hospitals can drive infections, supported by this organism's abilities to persist on dry surfaces and rapidly colonize susceptible individuals. To investigate how A. baumannii survives on surfaces, we cultured A. baumannii in liquid media for several days and then analyzed isolates that lost the ability to survive drying. One of these isolates carried a mutation that affected the gene encoding the carbon storage regulator CsrA. As we began to examine the role of CsrA in A. baumannii, we observed that the growth of ΔcsrA mutant strains was inhibited in the presence of amino acids. The ΔcsrA mutant strains had a reduced ability to survive drying and to form biofilms but an improved ability to tolerate increased osmolarity compared with the wild type. We also examined the importance of CsrA for A. baumannii virulence. The ΔcsrA mutant strains had a greatly reduced ability to kill Galleria mellonella larvae, could not replicate in G. mellonella hemolymph, and also had a growth defect in human serum. Together, these results show that CsrA is essential for the growth of A. baumannii on host-derived substrates and is involved in desiccation tolerance, implying that CsrA controls key functions involved in the transmission of A. baumannii in hospitals.
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Muir A, Gurung I, Cehovin A, Bazin A, Vallenet D, Pelicic V. Construction of a complete set of Neisseria meningitidis mutants and its use for the phenotypic profiling of this human pathogen. Nat Commun 2020; 11:5541. [PMID: 33139723 PMCID: PMC7606547 DOI: 10.1038/s41467-020-19347-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/05/2020] [Indexed: 01/29/2023] Open
Abstract
The bacterium Neisseria meningitidis causes life-threatening meningitis and sepsis. Here, we construct a complete collection of defined mutants in protein-coding genes of this organism, identifying all genes that are essential under laboratory conditions. The collection, named NeMeSys 2.0, consists of individual mutants in 1584 non-essential genes. We identify 391 essential genes, which are associated with basic functions such as expression and preservation of genome information, cell membrane structure and function, and metabolism. We use this collection to shed light on the functions of diverse genes, including a gene encoding a member of a previously unrecognised class of histidinol-phosphatases; a set of 20 genes required for type IV pili function; and several conditionally essential genes encoding antitoxins and/or immunity proteins. We expect that NeMeSys 2.0 will facilitate the phenotypic profiling of a major human bacterial pathogen.
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Affiliation(s)
- Alastair Muir
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Ishwori Gurung
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Ana Cehovin
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Adelme Bazin
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d'Evry, Université Paris-Saclay, CNRS, Evry, France
| | - David Vallenet
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, Université d'Evry, Université Paris-Saclay, CNRS, Evry, France
| | - Vladimir Pelicic
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK.
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Pardo I, Jha RK, Bermel RE, Bratti F, Gaddis M, McIntyre E, Michener W, Neidle EL, Dale T, Beckham GT, Johnson CW. Gene amplification, laboratory evolution, and biosensor screening reveal MucK as a terephthalic acid transporter in Acinetobacter baylyi ADP1. Metab Eng 2020; 62:260-274. [DOI: 10.1016/j.ymben.2020.09.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/11/2020] [Accepted: 09/19/2020] [Indexed: 12/19/2022]
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38
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Biggs BW, Bedore SR, Arvay E, Huang S, Subramanian H, McIntyre EA, Duscent-Maitland CV, Neidle EL, Tyo KEJ. Development of a genetic toolset for the highly engineerable and metabolically versatile Acinetobacter baylyi ADP1. Nucleic Acids Res 2020; 48:5169-5182. [PMID: 32246719 PMCID: PMC7229861 DOI: 10.1093/nar/gkaa167] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 02/20/2020] [Accepted: 03/04/2020] [Indexed: 01/10/2023] Open
Abstract
One primary objective of synthetic biology is to improve the sustainability of chemical manufacturing. Naturally occurring biological systems can utilize a variety of carbon sources, including waste streams that pose challenges to traditional chemical processing, such as lignin biomass, providing opportunity for remediation and valorization of these materials. Success, however, depends on identifying micro-organisms that are both metabolically versatile and engineerable. Identifying organisms with this combination of traits has been a historic hindrance. Here, we leverage the facile genetics of the metabolically versatile bacterium Acinetobacter baylyi ADP1 to create easy and rapid molecular cloning workflows, including a Cas9-based single-step marker-less and scar-less genomic integration method. In addition, we create a promoter library, ribosomal binding site (RBS) variants and test an unprecedented number of rationally integrated bacterial chromosomal protein expression sites and variants. At last, we demonstrate the utility of these tools by examining ADP1’s catabolic repression regulation, creating a strain with improved potential for lignin bioprocessing. Taken together, this work highlights ADP1 as an ideal host for a variety of sustainability and synthetic biology applications.
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Affiliation(s)
- Bradley W Biggs
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA.,Biotechnology Training Program, Northwestern University, Evanston, IL 60208, USA
| | - Stacy R Bedore
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Erika Arvay
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA.,Biotechnology Training Program, Northwestern University, Evanston, IL 60208, USA
| | - Shu Huang
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Harshith Subramanian
- Master of Science in Biotechnology Program, Northwestern University, Evanston, IL 60208, USA
| | - Emily A McIntyre
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | | | - Ellen L Neidle
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Keith E J Tyo
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA
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Suárez GA, Dugan KR, Renda BA, Leonard SP, Gangavarapu LS, Barrick JE. Rapid and assured genetic engineering methods applied to Acinetobacter baylyi ADP1 genome streamlining. Nucleic Acids Res 2020; 48:4585-4600. [PMID: 32232367 PMCID: PMC7192602 DOI: 10.1093/nar/gkaa204] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 03/15/2020] [Accepted: 03/18/2020] [Indexed: 01/10/2023] Open
Abstract
One goal of synthetic biology is to improve the efficiency and predictability of living cells by removing extraneous genes from their genomes. We demonstrate improved methods for engineering the genome of the metabolically versatile and naturally transformable bacterium Acinetobacter baylyi ADP1 and apply them to a genome streamlining project. In Golden Transformation, linear DNA fragments constructed by Golden Gate Assembly are directly added to cells to create targeted deletions, edits, or additions to the chromosome. We tested the dispensability of 55 regions of the ADP1 chromosome using Golden Transformation. The 18 successful multiple-gene deletions ranged in size from 21 to 183 kb and collectively accounted for 23.4% of its genome. The success of each multiple-gene deletion attempt could only be partially predicted on the basis of an existing collection of viable ADP1 single-gene deletion strains and a new transposon insertion sequencing (Tn-Seq) dataset that we generated. We further show that ADP1’s native CRISPR/Cas locus is active and can be retargeted using Golden Transformation. We reprogrammed it to create a CRISPR-Lock, which validates that a gene has been successfully removed from the chromosome and prevents it from being reacquired. These methods can be used together to implement combinatorial routes to further genome streamlining and for more rapid and assured metabolic engineering of this versatile chassis organism.
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Affiliation(s)
- Gabriel A Suárez
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Kyle R Dugan
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Brian A Renda
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Sean P Leonard
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Lakshmi Suryateja Gangavarapu
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Jeffrey E Barrick
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
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Abstract
Mutant phenotype analysis of bacteria has been revolutionized by genome-scale screening procedures, but essential genes have been left out of such studies because mutants are missing from the libraries analyzed. Since essential genes control the most fundamental processes of bacterial life, this is a glaring deficiency. To address this limitation, we developed a procedure for transposon insertion mutant sequencing that includes essential genes. The method, called transformation transposon insertion mutant sequencing (TFNseq), employs saturation-level libraries of bacterial mutants generated by natural transformation with chromosomal DNA mutagenized heavily by in vitro transposition. The efficient mutagenesis makes it possible to detect large numbers of insertions in essential genes immediately after transformation and to follow their loss during subsequent growth. It was possible to order 45 essential processes based on how rapidly their inactivation inhibited growth. Inactivating ATP production, deoxyribonucleotide synthesis, or ribosome production blocked growth the fastest, whereas inactivating cell division or outer membrane protein synthesis blocked it the slowest. Individual mutants deleted of essential loci formed microcolonies of nongrowing cells whose sizes were generally consistent with the TFNseq ordering. The sensitivity of essential functions to genetic inactivation provides a metric for ranking their relative importance for bacterial replication and growth. Highly sensitive functions could represent attractive antibiotic targets since even partial inhibition should reduce growth.
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41
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Hou YM, Masuda I, Foster LJ. tRNA methylation: An unexpected link to bacterial resistance and persistence to antibiotics and beyond. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 11:e1609. [PMID: 32533808 DOI: 10.1002/wrna.1609] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/06/2020] [Accepted: 05/07/2020] [Indexed: 02/02/2023]
Abstract
A major threat to public health is the resistance and persistence of Gram-negative bacteria to multiple drugs during antibiotic treatment. The resistance is due to the ability of these bacteria to block antibiotics from permeating into and accumulating inside the cell, while the persistence is due to the ability of these bacteria to enter into a nonreplicating state that shuts down major metabolic pathways but remains active in drug efflux. Resistance and persistence are permitted by the unique cell envelope structure of Gram-negative bacteria, which consists of both an outer and an inner membrane (OM and IM, respectively) that lay above and below the cell wall. Unexpectedly, recent work reveals that m1 G37 methylation of tRNA, at the N1 of guanosine at position 37 on the 3'-side of the tRNA anticodon, controls biosynthesis of both membranes and determines the integrity of cell envelope structure, thus providing a novel link to the development of bacterial resistance and persistence to antibiotics. The impact of m1 G37-tRNA methylation on Gram-negative bacteria can reach further, by determining the ability of these bacteria to exit from the persistence state when the antibiotic treatment is removed. These conceptual advances raise the possibility that successful targeting of m1 G37-tRNA methylation can provide new approaches for treating acute and chronic infections caused by Gram-negative bacteria. This article is categorized under: Translation > Translation Regulation RNA Processing > RNA Editing and Modification RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
- Ya-Ming Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Isao Masuda
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Leonard J Foster
- Department of Biochemistry & Molecular Biology, and Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
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42
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Luo J, Efimova E, Losoi P, Santala V, Santala S. Wax ester production in nitrogen-rich conditions by metabolically engineered Acinetobacter baylyi ADP1. Metab Eng Commun 2020; 10:e00128. [PMID: 32477866 PMCID: PMC7251950 DOI: 10.1016/j.mec.2020.e00128] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 04/18/2020] [Accepted: 04/19/2020] [Indexed: 11/29/2022] Open
Abstract
Metabolic engineering can be used as a powerful tool to redirect cell resources towards product synthesis, also in conditions that are not optimal for the production. An example of synthesis strongly dependent on external conditions is the production of storage lipids, which typically requires a high carbon/nitrogen ratio. This requirement also limits the use of abundant nitrogen-rich materials, such as industrial protein by-products, as substrates for lipid production. Acinetobacter baylyi ADP1 is known for its ability to produce industrially interesting storage lipids, namely wax esters (WEs). Here, we engineered A. baylyi ADP1 by deleting the gene aceA encoding for isocitrate lyase and overexpressing fatty acyl-CoA reductase Acr1 in the wax ester production pathway to allow redirection of carbon towards WEs. This strategy led to 3-fold improvement in yield (0.075 g/g glucose) and 3.15-fold improvement in titer (1.82 g/L) and productivity (0.038 g/L/h) by a simple one-stage batch cultivation with glucose as carbon source. The engineered strain accumulated up to 27% WEs of cell dry weight. The titer and cellular WE content are the highest reported to date among microbes. We further showed that the engineering strategy alleviated the inherent requirement for high carbon/nitrogen ratio and demonstrated the production of wax esters using nitrogen-rich substrates including casamino acids, yeast extract, and baker's yeast hydrolysate, which support biomass production but not WE production in wild-type cells. The study demonstrates the power of metabolic engineering in overcoming natural limitations in the production of storage lipids.
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Affiliation(s)
- Jin Luo
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Elena Efimova
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Pauli Losoi
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Ville Santala
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Suvi Santala
- Faculty of Engineering and Natural Sciences, Hervanta Campus, Tampere University, Korkeakoulunkatu 8, Tampere, 33720, Finland
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Vallenet D, Calteau A, Dubois M, Amours P, Bazin A, Beuvin M, Burlot L, Bussell X, Fouteau S, Gautreau G, Lajus A, Langlois J, Planel R, Roche D, Rollin J, Rouy Z, Sabatet V, Médigue C. MicroScope: an integrated platform for the annotation and exploration of microbial gene functions through genomic, pangenomic and metabolic comparative analysis. Nucleic Acids Res 2020; 48:D579-D589. [PMID: 31647104 PMCID: PMC7145621 DOI: 10.1093/nar/gkz926] [Citation(s) in RCA: 119] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/04/2019] [Accepted: 10/07/2019] [Indexed: 11/18/2022] Open
Abstract
Large-scale genome sequencing and the increasingly massive use of high-throughput approaches produce a vast amount of new information that completely transforms our understanding of thousands of microbial species. However, despite the development of powerful bioinformatics approaches, full interpretation of the content of these genomes remains a difficult task. Launched in 2005, the MicroScope platform (https://www.genoscope.cns.fr/agc/microscope) has been under continuous development and provides analysis for prokaryotic genome projects together with metabolic network reconstruction and post-genomic experiments allowing users to improve the understanding of gene functions. Here we present new improvements of the MicroScope user interface for genome selection, navigation and expert gene annotation. Automatic functional annotation procedures of the platform have also been updated and we added several new tools for the functional annotation of genes and genomic regions. We finally focus on new tools and pipeline developed to perform comparative analyses on hundreds of genomes based on pangenome graphs. To date, MicroScope contains data for >11 800 microbial genomes, part of which are manually curated and maintained by microbiologists (>4500 personal accounts in September 2019). The platform enables collaborative work in a rich comparative genomic context and improves community-based curation efforts.
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Affiliation(s)
- David Vallenet
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Alexandra Calteau
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Mathieu Dubois
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Paul Amours
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Adelme Bazin
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Mylène Beuvin
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Laura Burlot
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France.,UMS 3601 IFB-core, CNRS, INRA, INSERM, CEA & INRIA, Genoscope, Evry, 91057, France
| | - Xavier Bussell
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Stéphanie Fouteau
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Guillaume Gautreau
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Aurélie Lajus
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Jordan Langlois
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Rémi Planel
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - David Roche
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Johan Rollin
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Zoe Rouy
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Valentin Sabatet
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
| | - Claudine Médigue
- LABGeM, Génomique Métabolique, CEA, Genoscope, Institut François Jacob, CNRS, Université d'Évry, Université Paris-Saclay, Evry, 91057, France
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Zhou H, Zhang L, Xu Q, Zhang L, Yu Y, Hua X. The mismatch repair system (mutS and mutL) in Acinetobacter baylyi ADP1. BMC Microbiol 2020; 20:40. [PMID: 32111158 PMCID: PMC7048072 DOI: 10.1186/s12866-020-01729-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 02/14/2020] [Indexed: 02/06/2023] Open
Abstract
Background Acinetobacter baylyi ADP1 is an ideal bacterial strain for high-throughput genetic analysis as the bacterium is naturally transformable. Thus, ADP1 can be used to investigate DNA mismatch repair, a mechanism for repairing mismatched bases. We used the mutS deletion mutant (XH439) and mutL deletion mutant (XH440), and constructed a mutS mutL double deletion mutant (XH441) to investigate the role of the mismatch repair system in A. baylyi. Results We determined the survival rates after UV irradiation and measured the mutation frequencies, rates and spectra of wild-type ADP1 and mutSL mutant via rifampin resistance assay (RifR assay) and experimental evolution. In addition, transformation efficiencies of genomic DNA in ADP1 and its three mutants were determined. Lastly, the relative growth rates of the wild type strain, three constructed deletion mutants, as well as the rifampin resistant mutants obtained from RifR assays, were measured. All three mutants had higher survival rates after UV irradiation than wild type, especially the double deletion mutant. Three mutants showed higher mutation frequencies than ADP1 and favored transition mutations in RifR assay. All three mutants showed increased mutation rates in the experimental evolution. However, only XH439 and XH441 had higher mutation rates than the wild type strain in RifR assay. XH441 showed higher transformation efficiency than XH438 when donor DNA harbored transition mutations. All three mutants showed higher growth rates than wild-type, and these four strains displayed higher growth rates than almost all their rpoB mutants. The growth rate results showed different amino acid mutations in rpoB resulted in different extents of reduction in the fitness of rifampin resistant mutants. However, the fitness cost brought by the same mutation did not vary with strain background. Conclusions We demonstrated that inactivation of both mutS and mutL increased the mutation rates and frequencies in A. baylyi, which would contribute to the evolution and acquirement of rifampicin resistance. The mutS deletion is also implicated in increased mutation rates and frequencies, suggesting that MutL may be activated even in the absence of mutS. The correlation between fitness cost and rifampin resistance mutations in A. baylyi is firstly established.
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Affiliation(s)
- Hua Zhou
- Department of Respiratory Diseases, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Linyue Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Qingye Xu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Linghong Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China. .,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China.
| | - Xiaoting Hua
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China. .,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China.
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45
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Peterson MA, Grice AN, Hare JM. A corepressor participates in LexA-independent regulation of error-prone polymerases in Acinetobacter. MICROBIOLOGY (READING, ENGLAND) 2020; 166:212-226. [PMID: 31687925 PMCID: PMC7273328 DOI: 10.1099/mic.0.000866] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 10/07/2019] [Indexed: 01/03/2023]
Abstract
The DNA damage response of the multidrug-resistant pathogen Acinetobacter baumannii, which induces mutagenic UmuD'2C error-prone polymerases, differs from that of many bacteria. Acinetobacter species lack a LexA repressor, but induce gene transcription after DNA damage. One regulator, UmuDAb, binds to and represses the promoters of the multiple A. baumannii ATCC 17978 umuDC alleles and the divergently transcribed umuDAb and ddrR genes. ddrR is unique to the genus Acinetobacter and of unknown function. 5' RACE (rapid amplification of cDNA ends) PCR mapping of the umuDAb and ddrR transcriptional start sites revealed that their -35 promoter elements overlapped the UmuDAb binding site, suggesting that UmuDAb simultaneously repressed expression of both genes by blocking polymerase access. This coordinated control of ddrR and umuDAb suggested that ddrR might also regulate DNA damage-inducible gene transcription. RNA-sequencing experiments in 17 978 ddrR- cells showed that ddrR regulated approximately 25 % (n=39) of the mitomycin C-induced regulon, with umuDAb coregulating 17 of these ddrR-regulated genes. Eight genes (the umuDC polymerases, umuDAb and ddrR) were de-repressed in the absence of DNA damage, and nine genes were uninduced in the presence of DNA damage, in both ddrR and umuDAb mutant strains. These data suggest ddrR has multiple roles, both as a co-repressor and as a positive regulator of DNA damage-inducible gene transcription. Additionally, 57 genes were induced by mitomycin C in the ddrR mutant but not in wild-type cells. This regulon contained multiple genes for DNA replication, recombination and repair, transcriptional regulators, RND efflux, and transport. This study uncovered another regulator of the atypical DNA damage response of this genus, to help describe how this pathogen acquires drug resistance through its expression of the error-prone polymerases under DdrR and UmuDAb control.
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Affiliation(s)
- Megan A. Peterson
- Department of Biology and Chemistry, Morehead State University, Morehead, KY 40351, USA
| | - Alison N. Grice
- Department of Biology and Chemistry, Morehead State University, Morehead, KY 40351, USA
- Office of Information Technology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Janelle M. Hare
- Department of Biology and Chemistry, Morehead State University, Morehead, KY 40351, USA
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Losoi PS, Santala VP, Santala SM. Enhanced Population Control in a Synthetic Bacterial Consortium by Interconnected Carbon Cross-Feeding. ACS Synth Biol 2019; 8:2642-2650. [PMID: 31751122 DOI: 10.1021/acssynbio.9b00316] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Engineered microbial consortia can provide several advantages over monocultures in terms of utilization of mixed substrates, resistance to perturbations, and division of labor in complex tasks. However, maintaining stability, reproducibility, and control over population levels in variable conditions can be challenging in multispecies cultures. In our study, we modeled and constructed a synthetic symbiotic consortium with a genetically encoded carbon cross-feeding system. The system is based on strains of Escherichia coli and Acinetobacter baylyi ADP1, both engineered to be incapable of growing on glucose on their own. In a culture supplemented with glucose as the sole carbon source, growth of the two strains is afforded by the exchange of gluconate and acetate, resulting in inherent control over carbon availability and population balance. We investigated the system robustness in terms of stability and population control under different inoculation ratios, substrate concentrations, and cultivation scales, both experimentally and by modeling. To illustrate how the system might facilitate division of genetic circuits among synthetic microbial consortia, a green fluorescent protein sensitive to pH and a slowly maturing red fluorescent protein were expressed in the consortium as measures of a circuit's susceptibility to external and internal variability, respectively. The symbiotic consortium maintained stable and linear growth and circuit performance regardless of the initial substrate concentration or inoculation ratio. The developed cross-feeding system provides simple and reliable means for population control without expression of non-native elements or external inducer addition, being potentially exploitable in consortia applications involving precisely defined cell tasks or division of labor.
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Affiliation(s)
- Pauli S. Losoi
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta campus, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Ville P. Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta campus, Korkeakoulunkatu 8, Tampere, 33720, Finland
| | - Suvi M. Santala
- Faculty of Engineering and Natural Sciences, Tampere University, Hervanta campus, Korkeakoulunkatu 8, Tampere, 33720, Finland
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Jaroensuk J, Wong YH, Zhong W, Liew CW, Maenpuen S, Sahili AE, Atichartpongkul S, Chionh YH, Nah Q, Thongdee N, McBee ME, Prestwich EG, DeMott MS, Chaiyen P, Mongkolsuk S, Dedon PC, Lescar J, Fuangthong M. Crystal structure and catalytic mechanism of the essential m 1G37 tRNA methyltransferase TrmD from Pseudomonas aeruginosa. RNA (NEW YORK, N.Y.) 2019; 25:1481-1496. [PMID: 31399541 PMCID: PMC6795141 DOI: 10.1261/rna.066746.118] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 07/28/2019] [Indexed: 06/10/2023]
Abstract
The tRNA (m1G37) methyltransferase TrmD catalyzes m1G formation at position 37 in many tRNA isoacceptors and is essential in most bacteria, which positions it as a target for antibiotic development. In spite of its crucial role, little is known about TrmD in Pseudomonas aeruginosa (PaTrmD), an important human pathogen. Here we present detailed structural, substrate, and kinetic properties of PaTrmD. The mass spectrometric analysis confirmed the G36G37-containing tRNAs Leu(GAG), Leu(CAG), Leu(UAG), Pro(GGG), Pro(UGG), Pro(CGG), and His(GUG) as PaTrmD substrates. Analysis of steady-state kinetics with S-adenosyl-l-methionine (SAM) and tRNALeu(GAG) showed that PaTrmD catalyzes the two-substrate reaction by way of a ternary complex, while isothermal titration calorimetry revealed that SAM and tRNALeu(GAG) bind to PaTrmD independently, each with a dissociation constant of 14 ± 3 µM. Inhibition by the SAM analog sinefungin was competitive with respect to SAM (Ki = 0.41 ± 0.07 µM) and uncompetitive for tRNA (Ki = 6.4 ± 0.8 µM). A set of crystal structures of the homodimeric PaTrmD protein bound to SAM and sinefungin provide the molecular basis for enzyme competitive inhibition and identify the location of the bound divalent ion. These results provide insights into PaTrmD as a potential target for the development of antibiotics.
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Affiliation(s)
- Juthamas Jaroensuk
- Applied Biological Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
| | - Yee Hwa Wong
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | - Wenhe Zhong
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | - Chong Wai Liew
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | - Somchart Maenpuen
- Department of Biochemistry, Faculty of Science, Burapha University, Chonburi 20131, Thailand
| | - Abbas E Sahili
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | | | - Yok Hian Chionh
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
| | - Qianhui Nah
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
| | - Narumon Thongdee
- Applied Biological Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
| | - Megan E McBee
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
| | - Erin G Prestwich
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Michael S DeMott
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
| | - Skorn Mongkolsuk
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
- Department of Biotechnology, Faculty of Sciences, Mahidol University, Bangkok 10400, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), Bangkok 10400, Thailand
| | - Peter C Dedon
- Singapore-MIT Alliance for Research and Technology Antimicrobial Resistance and Infectious Disease Interdisciplinary Research Groups, 138602 Singapore
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Julien Lescar
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, 636921 Singapore
| | - Mayuree Fuangthong
- Applied Biological Sciences Program, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
- Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
- Center of Excellence on Environmental Health and Toxicology (EHT), Bangkok 10400, Thailand
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Morinière L, Lecomte S, Gueguen E, Bertolla F. In vitro exploration of the Xanthomonas hortorum pv. vitians genome using transposon insertion sequencing and comparative genomics to discriminate between core and contextual essential genes. Microb Genom 2019; 7. [PMID: 33760724 PMCID: PMC8627662 DOI: 10.1099/mgen.0.000546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The essential genome of a bacterium encompasses core genes associated with basic cellular processes and conditionally essential genes dependent upon environmental conditions or the genetic context. Comprehensive knowledge of those gene sets allows for a better understanding of fundamental bacterial biology and offers new perspectives for antimicrobial drug research against detrimental bacteria such as pathogens. We investigated the essential genome of Xanthomonas hortorum pv. vitians, a gammaproteobacterial plant pathogen of lettuce (Lactuca sativa L.) which belongs to the plant-pathogen reservoir genus Xanthomonas and is affiliated to the family Xanthomonadaceae. No practical means of disease control or prevention against this pathogen is currently available, and its molecular biology is virtually unknown. To reach a comprehensive overview of the essential genome of X. hortorum pv. vitians LM16734, we developed a mixed approach combining high-quality full genome sequencing, saturated transposon insertion sequencing (Tn-Seq) in optimal growth conditions, and coupled computational analyses such as comparative genomics, synteny assessment and phylogenomics. Among the 370 essential loci identified by Tn-Seq, a majority was bound to critical cell processes conserved across bacteria. The remaining genes were either related to specific ecological features of Xanthomonas or Xanthomonadaceae species, or acquired through horizontal gene transfer of mobile genetic elements and associated with ancestral parasitic gene behaviour and bacterial defence systems. Our study sheds new light on our usual concepts about gene essentiality and is pioneering in the molecular and genomic study of X. hortorum pv. vitians.
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Affiliation(s)
- Lucas Morinière
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F 69622 Villeurbanne, France
| | - Solène Lecomte
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F 69622 Villeurbanne, France
| | - Erwan Gueguen
- Univ Lyon, Université Claude Bernard Lyon 1, INSA, CNRS, UMR Microbiologie, Adaptation, Pathogénie, F 69622 Villeurbanne, France
| | - Franck Bertolla
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, INRAE, VetAgro Sup, UMR Ecologie Microbienne, F 69622 Villeurbanne, France
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ePath: an online database towards comprehensive essential gene annotation for prokaryotes. Sci Rep 2019; 9:12949. [PMID: 31506471 PMCID: PMC6737131 DOI: 10.1038/s41598-019-49098-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 08/15/2019] [Indexed: 02/01/2023] Open
Abstract
Experimental techniques for identification of essential genes (EGs) in prokaryotes are usually expensive, time-consuming and sometimes unrealistic. Emerging in silico methods provide alternative methods for EG prediction, but often possess limitations including heavy computational requirements and lack of biological explanation. Here we propose a new computational algorithm for EG prediction in prokaryotes with an online database (ePath) for quick access to the EG prediction results of over 4,000 prokaryotes ( https://www.pubapps.vcu.edu/epath/ ). In ePath, gene essentiality is linked to biological functions annotated by KEGG Ortholog (KO). Two new scoring systems, namely, E_score and P_score, are proposed for each KO as the EG evaluation criteria. E_score represents appearance and essentiality of a given KO in existing experimental results of gene essentiality, while P_score denotes gene essentiality based on the principle that a gene is essential if it plays a role in genetic information processing, cell envelope maintenance or energy production. The new EG prediction algorithm shows prediction accuracy ranging from 75% to 91% based on validation from five new experimental studies on EG identification. Our overall goal with ePath is to provide a comprehensive and reliable reference for gene essentiality annotation, facilitating the study of those prokaryotes without experimentally derived gene essentiality information.
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50
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Geisinger E, Huo W, Hernandez-Bird J, Isberg RR. Acinetobacter baumannii: Envelope Determinants That Control Drug Resistance, Virulence, and Surface Variability. Annu Rev Microbiol 2019; 73:481-506. [DOI: 10.1146/annurev-micro-020518-115714] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Acinetobacter baumannii has emerged as an important nosocomial pathogen, particularly for patients in intensive care units and with invasive indwelling devices. The most recent clinical isolates are resistant to several classes of clinically important antibiotics, greatly restricting the ability to effectively treat critically ill patients. The bacterial envelope is an important driver of A. baumannii disease, both at the level of battling against antibiotic therapy and at the level of protecting from host innate immune function. This review provides a comprehensive overview of key features of the envelope that interface with both the host and antimicrobial therapies. Carbohydrate structures that contribute to protecting from the host are detailed, and mutations that alter these structures, resulting in increased antimicrobial resistance, are explored. In addition, protein complexes involved in both intermicrobial and host-microbe interactions are described. Finally we discuss regulatory mechanisms that control the nature of the cell envelope and its impact on host innate immune function.
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Affiliation(s)
- Edward Geisinger
- Department of Biology, Northeastern University, Boston, Massachusetts 02115, USA
| | - Wenwen Huo
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Juan Hernandez-Bird
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Ralph R. Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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