1
|
Ríos-Alvarado J, Avitia-Rodríguez ON, Urtiz-Estrada N, Zazueta-Álvarez DE, López-Miranda J, Vázquez-Ortega PG, Rojas-Contreras JA. Expression and characterization of a novel β-1,4-endoglucanase from Bacillus subtilis strain isolated from a pulp and paper mill wastewater. Protein Expr Purif 2024; 220:106490. [PMID: 38697589 DOI: 10.1016/j.pep.2024.106490] [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: 01/28/2024] [Revised: 04/20/2024] [Accepted: 04/29/2024] [Indexed: 05/05/2024]
Abstract
The production of fermentable sugars from lignocellulosic biomass is achieved by the synergistic action of a group of enzymes called cellulases. Cellulose is a long chain of chemically linked glucoses by β-1,4 bonds. The enzyme β-1,4-endoglucanase is the first cellulase involved in the degradation, breaking the bond of the amorphous regions. A β-1,4-endoglucanase enzyme with high activity was obtained from a Bacillus subtilis strain isolated from wastewater of a pulp and paper mill. Sequencing and bioinformatic analysis showed that the gene amplified by PCR consisting of 1407 nucleotides and coding for a β-1,4-endoglucanase enzyme of approximately 55 kDa. The open reading frame (ORF) encoding the mature endoglucanase (eglS) was successfully inserted in a modified cloning plasmid (pITD03) and into the pYD1 plasmid used for its expression in yeast. Carboxymethylcellulose (CMC) plate assay, SDS-PAGE, and zymogram confirmed the production and secretion by the transformed E. coli BL21-SI strain of a 39 kDa β-1,4-endoglucanase consistent with the catalytic domain without the cellulose-binding module (CBM). The results showed that the truncated β-1,4-endoglucanase had higher activity and stability.
Collapse
Affiliation(s)
- Joel Ríos-Alvarado
- Tecnológico Nacional de México/Instituto Tecnológico de Durango, Blvd. Felipe Pescador 1830 Ote. Col. Nueva Vizcaya, 34080, Durango, Dgo., Mexico
| | - Olga Noelia Avitia-Rodríguez
- Tecnológico Nacional de México/Instituto Tecnológico de Durango, Blvd. Felipe Pescador 1830 Ote. Col. Nueva Vizcaya, 34080, Durango, Dgo., Mexico
| | - Norma Urtiz-Estrada
- Facultad de Ciencias Químicas, Universidad Juárez del Estado de Durango, Av. Veterinaria S/N, Col. Valle del Sur, 34120, Durango, Dgo., Mexico
| | - David Enrique Zazueta-Álvarez
- Universidad Politécnica de Durango, Departamento de Ingeniería en Tecnología Ambiental, Carretera Durango-México Km 9.5. Col, Los Encinos, C.P. 34300, Durango, Dgo, Mexico
| | - Javier López-Miranda
- Tecnológico Nacional de México/Instituto Tecnológico de Durango, Blvd. Felipe Pescador 1830 Ote. Col. Nueva Vizcaya, 34080, Durango, Dgo., Mexico
| | - Perla Guadalupe Vázquez-Ortega
- Tecnológico Nacional de México/Instituto Tecnológico de Durango, Blvd. Felipe Pescador 1830 Ote. Col. Nueva Vizcaya, 34080, Durango, Dgo., Mexico.
| | - Juan Antonio Rojas-Contreras
- Tecnológico Nacional de México/Instituto Tecnológico de Durango, Blvd. Felipe Pescador 1830 Ote. Col. Nueva Vizcaya, 34080, Durango, Dgo., Mexico.
| |
Collapse
|
2
|
Maybin M, Ranade AM, Schombel U, Gisch N, Mamat U, Meredith TC. IS 1-mediated chromosomal amplification of the arn operon leads to polymyxin B resistance in Escherichia coli B strains. mBio 2024:e0063424. [PMID: 38904391 DOI: 10.1128/mbio.00634-24] [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: 02/29/2024] [Accepted: 05/14/2024] [Indexed: 06/22/2024] Open
Abstract
Polymyxins [colistin and polymyxin B (PMB)] comprise an important class of natural product lipopeptide antibiotics used to treat multidrug-resistant Gram-negative bacterial infections. These positively charged lipopeptides interact with lipopolysaccharide (LPS) located in the outer membrane and disrupt the permeability barrier, leading to increased uptake and bacterial cell death. Many bacteria counter polymyxins by upregulating genes involved in the biosynthesis and transfer of amine-containing moieties to increase positively charged residues on LPS. Although 4-deoxy-l-aminoarabinose (Ara4N) and phosphoethanolamine (PEtN) are highly conserved LPS modifications in Escherichia coli, different lineages exhibit variable PMB susceptibilities and frequencies of resistance for reasons that are poorly understood. Herein, we describe a mechanism prevalent in E. coli B strains that depends on specific insertion sequence 1 (IS1) elements that flank genes involved in the biosynthesis and transfer of Ara4N to LPS. Spontaneous and transient chromosomal amplifications mediated by IS1 raise the frequency of PMB resistance by 10- to 100-fold in comparison to strains where a single IS1 element located 90 kb away from the end of the arn operon has been deleted. Amplification involving IS1 becomes the dominant resistance mechanism in the absence of PEtN modification. Isolates with amplified arn operons gradually lose their PMB-resistant phenotype with passaging, consistent with classical PMB heteroresistance behavior. Analysis of the whole genome transcriptome profile showed altered expression of genes residing both within and outside of the duplicated chromosomal segment, suggesting complex phenotypes including PMB resistance can result from tandem amplification events.IMPORTANCEPhenotypic variation in susceptibility and the emergence of resistant subpopulations are major challenges to the clinical use of polymyxins. While a large database of genes and alleles that can confer polymyxin resistance has been compiled, this report demonstrates that the chromosomal insertion sequence (IS) content and distribution warrant consideration as well. Amplification of large chromosomal segments containing the arn operon by IS1 increases the Ara4N content of the lipopolysaccharide layer in Escherichia coli B lineages using a mechanism that is orthogonal to transcriptional upregulation through two-component regulatory systems. Altogether, our work highlights the importance of IS elements in modulating gene expression and generating diverse subpopulations that can contribute to phenotypic polymyxin B heteroresistance.
Collapse
Affiliation(s)
- Michael Maybin
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Aditi M Ranade
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Ursula Schombel
- Division of Bioanalytical Chemistry, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Nicolas Gisch
- Division of Bioanalytical Chemistry, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, Borstel, Germany
| | - Uwe Mamat
- Division of Cellular Microbiology, Priority Research Area Infections, Research Center Borstel, Leibniz Lung Center, Leibniz Research Alliance INFECTIONS, Borstel, Germany
| | - Timothy C Meredith
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
- The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania, USA
| |
Collapse
|
3
|
Recio M, de la Torre J, Daddaoua A, Udaondo Z, Duque E, Gavira JA, López‐Sánchez C, Ramos JL. Characterization of an extremophile bacterial acid phosphatase derived from metagenomics analysis. Microb Biotechnol 2024; 17:e14404. [PMID: 38588312 PMCID: PMC11001196 DOI: 10.1111/1751-7915.14404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 04/10/2024] Open
Abstract
Acid phosphatases are enzymes that play a crucial role in the hydrolysis of various organophosphorous molecules. A putative acid phosphatase called FS6 was identified using genetic profiles and sequences from different environments. FS6 showed high sequence similarity to type C acid phosphatases and retained more than 30% of consensus residues in its protein sequence. A histidine-tagged recombinant FS6 produced in Escherichia coli exhibited extremophile properties, functioning effectively in a broad pH range between 3.5 and 8.5. The enzyme demonstrated optimal activity at temperatures between 25 and 50°C, with a melting temperature of 51.6°C. Kinetic parameters were determined using various substrates, and the reaction catalysed by FS6 with physiological substrates was at least 100-fold more efficient than with p-nitrophenyl phosphate. Furthermore, FS6 was found to be a decamer in solution, unlike the dimeric forms of crystallized proteins in its family.
Collapse
Affiliation(s)
- Maria‐Isabel Recio
- Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Department of Environmental ProtectionGranadaSpain
| | - Jesús de la Torre
- Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Department of Environmental ProtectionGranadaSpain
| | - Abdelali Daddaoua
- Department of Biochemistry and Molecular Biology II, Pharmacy SchoolGranada UniversityGranadaSpain
| | - Zulema Udaondo
- Department of Biomedical Informatics, College of Medicine, University of Arkansas for Medical SciencesLittle RockArkansasUSA
| | - Estrella Duque
- Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Department of Environmental ProtectionGranadaSpain
| | - José Antonio Gavira
- Consejo Superior de Investigaciones Científicas, Instituto de Ciencias de la TierraGranadaSpain
| | - Carmen López‐Sánchez
- Consejo Superior de Investigaciones Científicas, Instituto de Ciencias de la TierraGranadaSpain
| | - Juan L. Ramos
- Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Department of Environmental ProtectionGranadaSpain
| |
Collapse
|
4
|
Höhmann S, Briol TA, Ihle N, Frick O, Schmid A, Bühler B. Glycolate as alternative carbon source for Escherichia coli. J Biotechnol 2024; 381:76-85. [PMID: 38190849 DOI: 10.1016/j.jbiotec.2024.01.001] [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: 10/04/2023] [Revised: 12/20/2023] [Accepted: 01/01/2024] [Indexed: 01/10/2024]
Abstract
The physiology of different Escherichia coli stains was analyzed for growth with glycolate as a potentially promising sustainable sole source of carbon and energy. Different E. coli strains showed large differences regarding lag phases after provision of glycolate. Whereas E. coli W showed fast adaptation, E. coli BW25113, JM101, and BL21 (DE3) needed extensive time for adaption (up to 30 generations) until the attainable µmax was reached, which, at 30 °C, amounted to 0.20-0.25 h-1 for all strains. The overexpression of genes encoding glycolate degradation did neither overcome the need for adaptation of E. coli BL21 (DE3) nor improve growth of E. coli W. Rather, high level expression of proteins involved in uptake and initial degradation steps had an adverse effect on growth. Overall, the results show a promising capacity of E. coli strains for growth on glycolate.
Collapse
Affiliation(s)
- Sonja Höhmann
- Department of Solar Materials, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany; Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Tim Arik Briol
- Department of Solar Materials, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany; Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Nadine Ihle
- Department of Solar Materials, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Oliver Frick
- Department of Solar Materials, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Andreas Schmid
- Department of Solar Materials, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany
| | - Bruno Bühler
- Department of Solar Materials, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany; Department of Microbial Biotechnology, Helmholtz Centre for Environmental Research GmbH - UFZ, Leipzig, Germany.
| |
Collapse
|
5
|
Vazulka S, Schiavinato M, Tauer C, Wagenknecht M, Cserjan-Puschmann M, Striedner G. RNA-seq reveals multifaceted gene expression response to Fab production in Escherichia coli fed-batch processes with particular focus on ribosome stalling. Microb Cell Fact 2024; 23:14. [PMID: 38183013 PMCID: PMC10768439 DOI: 10.1186/s12934-023-02278-w] [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: 10/12/2023] [Accepted: 12/18/2023] [Indexed: 01/07/2024] Open
Abstract
BACKGROUND Escherichia coli is a cost-effective expression system for production of antibody fragments like Fabs. Various yield improvement strategies have been applied, however, Fabs remain challenging to produce. This study aimed to characterize the gene expression response of commonly used E. coli strains BL21(DE3) and HMS174(DE3) to periplasmic Fab expression using RNA sequencing (RNA-seq). Two Fabs, Fabx and FTN2, fused to a post-translational translocation signal sequence, were produced in carbon-limited fed-batch cultivations. RESULTS Production of Fabx impeded cell growth substantially stronger than FTN2 and yields of both Fabs differed considerably. The most noticeable, common changes in Fab-producing cells suggested by our RNA-seq data concern the cell envelope. The Cpx and Psp stress responses, both connected to inner membrane integrity, were activated, presumably by recombinant protein aggregation and impairment of the Sec translocon. The data additionally suggest changes in lipopolysaccharide synthesis, adjustment of membrane permeability, and peptidoglycan maturation and remodeling. Moreover, all Fab-producing strains showed depletion of Mg2+, indicated by activation of the PhoQP two-component signal transduction system during the early stage and sulfur and phosphate starvation during the later stage of the process. Furthermore, our data revealed ribosome stalling, caused by the Fabx amino acid sequence, as a contributor to low Fabx yields. Increased Fabx yields were obtained by a site-specific amino acid exchange replacing the stalling sequence. Contrary to expectations, cell growth was not impacted by presence or removal of the stalling sequence. Considering ribosome rescue is a conserved mechanism, the substantial differences observed in gene expression between BL21(DE3) and HMS174(DE3) in response to ribosome stalling on the recombinant mRNA were surprising. CONCLUSIONS Through characterization of the gene expression response to Fab production under industrially relevant cultivation conditions, we identified potential cell engineering targets. Thereby, we hope to enable rational approaches to improve cell fitness and Fab yields. Furthermore, we highlight ribosome stalling caused by the amino acid sequence of the recombinant protein as a possible challenge during recombinant protein production.
Collapse
Affiliation(s)
- Sophie Vazulka
- Christian Doppler Laboratory for Production of Next-Level Biopharmaceuticals in E. Coli, Department of Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190, Vienna, Austria
| | - Matteo Schiavinato
- Department of Biotechnology, Institute of Computational Biology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190, Vienna, Austria
| | - Christopher Tauer
- Christian Doppler Laboratory for Production of Next-Level Biopharmaceuticals in E. Coli, Department of Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190, Vienna, Austria
| | - Martin Wagenknecht
- Boehringer Ingelheim RCV, GmbH & Co KG, Dr.-Boehringer-Gasse 5-11, A-1120, Vienna, Austria
| | - Monika Cserjan-Puschmann
- Christian Doppler Laboratory for Production of Next-Level Biopharmaceuticals in E. Coli, Department of Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190, Vienna, Austria.
| | - Gerald Striedner
- Christian Doppler Laboratory for Production of Next-Level Biopharmaceuticals in E. Coli, Department of Biotechnology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190, Vienna, Austria
| |
Collapse
|
6
|
García Vázquez A, Mitarai N, Jauffred L. Genetic mixing and demixing on expanding spherical frontiers. ISME COMMUNICATIONS 2024; 4:ycae009. [PMID: 38524760 PMCID: PMC10958774 DOI: 10.1093/ismeco/ycae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 03/26/2024]
Abstract
Genetic fluctuation during range expansion is a key process driving evolution. When a bacterial population is expanding on a 2D surface, random fluctuations in the growth of the pioneers at the front line cause a strong demixing of genotypes. Even when there is no selective advantage, sectors of low genetic diversity are formed. Experimental studies of range expansions in surface-attached colonies of fluorescently labelled micro-organisms have contributed significantly to our understanding of fundamental evolutionary dynamics. However, experimental studies on genetic fluctuations in 3D range expansions have been sparse, despite their importance for tumour or biofilm development. We encapsulated populations of two fluorescent Escherichia coli strains in inoculation droplets (volumes [Formula: see text] nl). The confined ensemble of cells grew when embedded in a hydrogel-with nutrients-and developed 3D colonies with well-defined, sector-like regions. Using confocal laser scanning microscopy, we imaged the development of 3D colonies and the emergence of sectors. We characterized how cell concentration in the inoculation droplet controls sectors, growth rate, and the transition from branched colonies to quasi-spherical colonies. We further analysed how sectors on the surface change over time. We complement these experimental results with a modified 3D Eden growth model. The model in 3D spherical growth predicts a phase, where sectors are merging, followed by a steady increase (constant rate), and the experimentally analysed sectors were consistent with this prediction. Therefore, our results demonstrate qualitative differences between radial (2D) and spherical (3D) range expansions and their importance in gene fixation processes.
Collapse
Affiliation(s)
- Alba García Vázquez
- The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen O, Denmark
| | - Namiko Mitarai
- The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen O, Denmark
| | - Liselotte Jauffred
- The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen O, Denmark
| |
Collapse
|
7
|
Weaver BR, Perkins LJ, Fernandez Candelaria FO, Burstyn JN, Buller AR. Molecular Determinants of Efficient Cobalt-Substituted Hemoprotein Production in E. coli. ACS Synth Biol 2023; 12:3669-3679. [PMID: 37963151 DOI: 10.1021/acssynbio.3c00481] [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] [Indexed: 11/16/2023]
Abstract
Exchanging the native iron of heme for other metals yields artificial metalloproteins with new properties for spectroscopic studies and biocatalysis. Recently, we reported a method for the biosynthesis and incorporation of a non-natural metallocofactor, cobalt protoporphyrin IX (CoPPIX), into hemoproteins using the common laboratory strain Escherichia coli BL21(DE3). This discovery inspired us to explore the determinants of metal specificity for metallocofactor biosynthesis in E. coli. Herein, we report detailed kinetic analysis of the ferrochelatase responsible for metal insertion, EcHemH (E. coli ferrochelatase). This enzyme exhibits a small, less than 2-fold preference for Fe2+ over the non-native Co2+ substrate in vitro. To test how mutations impact EcHemH, we used a surrogate metal specificity screen to identify variants with altered metal insertion preferences. This engineering process led to a variant with an ∼30-fold shift in specificity toward Co2+. When assayed in vivo, however, the impact of this mutation is small compared to the effects of alteration of the external metal concentrations. These data suggest that incorporation of cobalt into PPIX is enabled by the native promiscuity of EcHemH coupled with BL21's impaired ability to maintain transition-metal homeostasis. With this knowledge, we generated a method for CoPPIX production in rich media, which yields cobalt-substituted hemoproteins with >95% cofactor purity and yields comparable to standard expression protocols for the analogous native hemoproteins.
Collapse
Affiliation(s)
- Brian R Weaver
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Lydia J Perkins
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | | | - Judith N Burstyn
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Andrew R Buller
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| |
Collapse
|
8
|
Frézal L, Saglio M, Zhang G, Noble L, Richaud A, Félix MA. Genome-wide association and environmental suppression of the mortal germline phenotype of wild C. elegans. EMBO Rep 2023; 24:e58116. [PMID: 37983674 DOI: 10.15252/embr.202358116] [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: 09/05/2023] [Revised: 10/19/2023] [Accepted: 10/27/2023] [Indexed: 11/22/2023] Open
Abstract
The animal germline lineage needs to be maintained along generations. However, some Caenorhabditis elegans wild isolates display a mortal germline phenotype, leading to sterility after several generations at 25°C. Using a genome-wide association approach, we detect a significant peak on chromosome III around 5 Mb, confirmed by introgressions. Thus, a seemingly deleterious genotype is maintained at intermediate frequency in the species. Environmental rescue is a likely explanation, and indeed associated bacteria and microsporidia suppress the phenotype of wild isolates as well as mutants in small RNA inheritance (nrde-2) and histone modifications (set-2). Escherichia coli strains of the K-12 lineage suppress the phenotype compared to B strains. By shifting a wild strain from E. coli K-12 to E. coli B, we find that memory of the suppressing condition is maintained over several generations. Thus, the mortal germline phenotype of wild C. elegans is in part revealed by laboratory conditions and may represent variation in epigenetic inheritance and environmental interactions. This study also points to the importance of non-genetic memory in the face of environmental variation.
Collapse
Affiliation(s)
- Lise Frézal
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, Paris, France
| | - Marie Saglio
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, Paris, France
| | - Gaotian Zhang
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, Paris, France
| | - Luke Noble
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, Paris, France
| | - Aurélien Richaud
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, Paris, France
| | - Marie-Anne Félix
- Institut de Biologie de l'Ecole Normale Supérieure, CNRS, Inserm, Paris, France
| |
Collapse
|
9
|
Shishparenok AN, Gladilina YA, Zhdanov DD. Engineering and Expression Strategies for Optimization of L-Asparaginase Development and Production. Int J Mol Sci 2023; 24:15220. [PMID: 37894901 PMCID: PMC10607044 DOI: 10.3390/ijms242015220] [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: 09/21/2023] [Revised: 10/11/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Genetic engineering for heterologous expression has advanced in recent years. Model systems such as Escherichia coli, Bacillus subtilis and Pichia pastoris are often used as host microorganisms for the enzymatic production of L-asparaginase, an enzyme widely used in the clinic for the treatment of leukemia and in bakeries for the reduction of acrylamide. Newly developed recombinant L-asparaginase (L-ASNase) may have a low affinity for asparagine, reduced catalytic activity, low stability, and increased glutaminase activity or immunogenicity. Some successful commercial preparations of L-ASNase are now available. Therefore, obtaining novel L-ASNases with improved properties suitable for food or clinical applications remains a challenge. The combination of rational design and/or directed evolution and heterologous expression has been used to create enzymes with desired characteristics. Computer design, combined with other methods, could make it possible to generate mutant libraries of novel L-ASNases without costly and time-consuming efforts. In this review, we summarize the strategies and approaches for obtaining and developing L-ASNase with improved properties.
Collapse
Affiliation(s)
- Anastasiya N. Shishparenok
- Laboratory of Medical Biotechnology, Institute of Biomedical Chemistry, Pogodinskaya St. 10/8, 119121 Moscow, Russia; (A.N.S.); (Y.A.G.)
| | - Yulia A. Gladilina
- Laboratory of Medical Biotechnology, Institute of Biomedical Chemistry, Pogodinskaya St. 10/8, 119121 Moscow, Russia; (A.N.S.); (Y.A.G.)
| | - Dmitry D. Zhdanov
- Laboratory of Medical Biotechnology, Institute of Biomedical Chemistry, Pogodinskaya St. 10/8, 119121 Moscow, Russia; (A.N.S.); (Y.A.G.)
- Department of Biochemistry, Peoples’ Friendship University of Russia named after Patrice Lumumba (RUDN University), Miklukho—Maklaya St. 6, 117198 Moscow, Russia
| |
Collapse
|
10
|
Lenski RE. Revisiting the Design of the Long-Term Evolution Experiment with Escherichia coli. J Mol Evol 2023; 91:241-253. [PMID: 36790511 DOI: 10.1007/s00239-023-10095-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 01/20/2023] [Indexed: 02/16/2023]
Abstract
The long-term evolution experiment (LTEE) with Escherichia coli began in 1988 and it continues to this day, with its 12 populations having recently reached 75,000 generations of evolution in a simple, well-controlled environment. The LTEE was designed to explore open-ended questions about the dynamics and repeatability of phenotypic and genetic evolution. Here I discuss various aspects of the LTEE's experimental design that have enabled its stability and success, including the choices of the culture regime, growth medium, ancestral strain, and statistical replication. I also discuss some of the challenges associated with a long-running project, such as handling procedural errors (e.g., cross-contamination) and managing the expanding collection of frozen samples. The simplicity of the experimental design and procedures have supported the long-term stability of the LTEE. That stability-along with the inherent creativity of the evolutionary process and the emergence of new genomic technologies-provides a platform that has allowed talented students and collaborators to pose questions, collect data, and make discoveries that go far beyond anything I could have imagined at the start of the LTEE.
Collapse
Affiliation(s)
- Richard E Lenski
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA.
- Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI, 48824, USA.
| |
Collapse
|
11
|
Rao SN, Kumari GM, Srividya D, Anil HS, Lakshmikanth M, Naik H, Prabhuraj A. Validation of Lon Gene Disruption using Linear DNA Cassette by Crelox Mechanism in E. coli Strains: To Achieve Better Solubility of Putrescine Monooxygenase. Indian J Microbiol 2023; 63:56-64. [PMID: 37188228 PMCID: PMC10172422 DOI: 10.1007/s12088-023-01056-x] [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: 10/08/2022] [Accepted: 01/14/2023] [Indexed: 02/05/2023] Open
Abstract
Numerous expression systems, engineered strains, and cultivation systems have been developed globally but producing recombinant proteins in the soluble form continues to remain a challenge. Escherichia coli, a preferred host for the recombinant production of biopharmaceuticals and other proteins. Up to 75% of human proteins expressed in E. coli have only 25% in an active soluble form. The proteolytic activity of Lon encoded protease triggers the inclusion bodies leading to heterogenous secreted proteins thereby hampering downstream processing and isolation. Putrescine monooxygenases are versatile with applications in iron acquisition, pathogen control, biotransformation, bio-remediation and redox reaction are still isolated from plant and microbial sources at low yields. As a prerequisite to developing protease knockout E. coli strains, using the Cre-loxP recombination strategy we have built a full-length Lon disruption cassette (5'lon-lox66-cre-KanR-lox71-3'lon) (3368 bp) consisting of upstream and downstream regions of Lon, loxP sites, and Cre gene driven by T7 promoter to the expression of Cre recombinase and a selectable kanamycin resistance gene. Here, after the integration of the knock-out cassette into the host genome, we show the production of homogeneous protein species of recombinant Putrescine monooxygenase by using an E. coli platform strain in which Lon gene is deleted. This Lon knock-out strain secreted more homogeneous protein at a volumetric yield of 60% of the wild-type strain. Supplementary Information The online version contains supplementary material available at 10.1007/s12088-023-01056-x.
Collapse
Affiliation(s)
- Saroja Narsing Rao
- Pesticide Residue and Food Quality Analysis Laboratory, University of Agricultural Sciences, Raichur, 584104 Karnataka India
| | - G. Monika Kumari
- Pesticide Residue and Food Quality Analysis Laboratory, University of Agricultural Sciences, Raichur, 584104 Karnataka India
| | - D. Srividya
- Pesticide Residue and Food Quality Analysis Laboratory, University of Agricultural Sciences, Raichur, 584104 Karnataka India
| | - H. S. Anil
- Department of Biotechnology, Dayananda Sagar College of Engineering, KS Layout, Shavige Malleswara Hills, Bengaluru-78, Karnataka India
| | - M. Lakshmikanth
- Pesticide Residue and Food Quality Analysis Laboratory, University of Agricultural Sciences, Raichur, 584104 Karnataka India
- College of Agriculture, University of Agricultural Sciences, Raichur, India
| | - Harishchandra Naik
- Pesticide Residue and Food Quality Analysis Laboratory, University of Agricultural Sciences, Raichur, 584104 Karnataka India
| | - A. Prabhuraj
- Pesticide Residue and Food Quality Analysis Laboratory, University of Agricultural Sciences, Raichur, 584104 Karnataka India
| |
Collapse
|
12
|
Fromm SA, O'Connor KM, Purdy M, Bhatt PR, Loughran G, Atkins JF, Jomaa A, Mattei S. The translating bacterial ribosome at 1.55 Å resolution generated by cryo-EM imaging services. Nat Commun 2023; 14:1095. [PMID: 36841832 PMCID: PMC9968351 DOI: 10.1038/s41467-023-36742-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 02/15/2023] [Indexed: 02/26/2023] Open
Abstract
Our understanding of protein synthesis has been conceptualised around the structure and function of the bacterial ribosome. This complex macromolecular machine is the target of important antimicrobial drugs, an integral line of defence against infectious diseases. Here, we describe how open access to cryo-electron microscopy facilities combined with bespoke user support enabled structural determination of the translating ribosome from Escherichia coli at 1.55 Å resolution. The obtained structures allow for direct determination of the rRNA sequence to identify ribosome polymorphism sites in the E. coli strain used in this study and enable interpretation of the ribosomal active and peripheral sites at unprecedented resolution. This includes scarcely populated chimeric hybrid states of the ribosome engaged in several tRNA translocation steps resolved at ~2 Å resolution. The current map not only improves our understanding of protein synthesis but also allows for more precise structure-based drug design of antibiotics to tackle rising bacterial resistance.
Collapse
Affiliation(s)
- Simon A Fromm
- EMBL Imaging Centre, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany
| | - Kate M O'Connor
- School of Biochemistry and Cell Biology, University College Cork, Cork, T12 XF62, Ireland
| | - Michael Purdy
- Department of Molecular Physiology and Biological Physics, School of Medicine, University of Virginia, Charlottesville, VA, USA
| | - Pramod R Bhatt
- School of Biochemistry and Cell Biology, University College Cork, Cork, T12 XF62, Ireland
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, T12 XF62, Ireland
| | - John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, T12 XF62, Ireland. .,MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.
| | - Ahmad Jomaa
- Department of Molecular Physiology and Biological Physics, School of Medicine, University of Virginia, Charlottesville, VA, USA. .,Centre for Cell and Membrane Physiology, University of Virginia, Charlottesville, VA, USA.
| | - Simone Mattei
- EMBL Imaging Centre, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany. .,Structural and Computational Biology Unit, European Molecular Biology Laboratory, Meyerhofstraße 1, 69117, Heidelberg, Germany.
| |
Collapse
|
13
|
Wang Q, Li J, Yang J, Zou Y, Zhao XQ. Diversity of endophytic bacterial and fungal microbiota associated with the medicinal lichen Usnea longissima at high altitudes. Front Microbiol 2022; 13:958917. [PMID: 36118246 PMCID: PMC9479685 DOI: 10.3389/fmicb.2022.958917] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/12/2022] [Indexed: 11/29/2022] Open
Abstract
Endophytic microbial communities of lichen are emerging as novel microbial resources and for exploration of potential biotechnological applications. Here, we focused on a medicinal lichen Usnea longissima, and investigated its bacterial and fungal endophytes. Using PacBio 16S rRNA and ITS amplicon sequencing, we explored the diversity and composition of endophytic bacteria and fungi in U. longissima collected from Tibet at five altitudes ranging from 2,989 to 4,048 m. A total of 6 phyla, 12 classes, 44 genera, and 13 species of the bacterial community have been identified in U. longissima. Most members belong to Alphaproteobacteria (42.59%), Betaproteobacteria (33.84%), Clostridia (13.59%), Acidobacteria (7%), and Bacilli (1.69%). As for the fungal community, excluding the obligate fungus sequences, we identified 2 phyla, 15 classes, 65 genera, and 19 species. Lichen-related fungi of U. longissima mainly came from Ascomycota (95%), Basidiomycota (2.69%), and unidentified phyla (2.5%). The presence of the sequences that have not been characterized before suggests the novelty of the microbiota. Of particular interest is the detection of sequences related to lactic acid bacteria and budding yeast. In addition, the possible existence of harmful bacteria was also discussed. To our best knowledge, this is the first relatively detailed study on the endophytic microbiota associated with U. longissima. The results here provide the basis for further exploration of the microbial diversity in lichen and promote biotechnological applications of lichen-associated microbial strains.
Collapse
Affiliation(s)
- Qi Wang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Jun Li
- R&D Center, JALA Group Co., Ltd., Shanghai, China
| | - Jie Yang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yue Zou
- R&D Center, JALA Group Co., Ltd., Shanghai, China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Xin-Qing Zhao,
| |
Collapse
|
14
|
Li M, Wang Z, Zhou M, Zhang C, Zhi K, Liu S, Sun X, Wang Z, Liu J, Liu D. Continuous Production of Human Epidermal Growth Factor Using Escherichia coli Biofilm. Front Microbiol 2022; 13:855059. [PMID: 35495696 PMCID: PMC9039743 DOI: 10.3389/fmicb.2022.855059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 02/22/2022] [Indexed: 11/13/2022] Open
Abstract
Increasing demand for recombinant proteins necessitates efficient protein production processes. In this study, a continuous process for human epidermal growth factor (hEGF) secretion by Escherichia coli was developed by taking advantage of biofilm formation. Genes bcsB, fimH, and csgAcsgB that have proved to facilitate biofilm formation and some genes moaE, yceA, ychJ, and gshB potentially involved in biofilm formation were examined for their effects on hEGF secretion as well as biofilm formation. Finally, biofilm-based fermentation processes were established, which demonstrated the feasibility of continuous production of hEGF with improved efficiency. The best result was obtained from ychJ-disruption that showed a 28% increase in hEGF secretion over the BL21(DE3) wild strain, from 24 to 32 mg/L. Overexpression of bcsB also showed great potential in continuous immobilized fermentation. Overall, the biofilm engineering here represents an effective strategy to improve hEGF production and can be adapted to produce more recombinant proteins in future.
Collapse
Affiliation(s)
- Mengting Li
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.,School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Zhenyu Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Miao Zhou
- School of Life Sciences, Zhengzhou University, Zhengzhou, China
| | - Chong Zhang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China
| | - Kaiqi Zhi
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, China
| | - Shuli Liu
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, China
| | - Xiujuan Sun
- Institute of Industrial Biotechnology, Jiangsu Industrial Technology Research Institute (JITRI), Nanjing, China
| | - Zhi Wang
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, China
| | - Jinle Liu
- School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, China
| | - Dong Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, China.,School of Chemical Engineering and Energy, Zhengzhou University, Zhengzhou, China.,Institute of Industrial Biotechnology, Jiangsu Industrial Technology Research Institute (JITRI), Nanjing, China
| |
Collapse
|
15
|
Militello KT, Nedelkovska H. An undergraduate laboratory to detect viruses in human DNA samples using qPCR. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION : A BIMONTHLY PUBLICATION OF THE INTERNATIONAL UNION OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 50:319-325. [PMID: 35412013 DOI: 10.1002/bmb.21620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
The COVID-19 pandemic has necessitated the need to reliably detect the presence of viral genomes in human clinical samples. The most accurate viral tests involve the use of qPCR. Thus, it is important for students to understand the mechanism to detect viral genomes by qPCR including critical qPCR controls and how to properly interpret qPCR data. Herein, we describe a 2-week undergraduate laboratory to detect a viral genome in a human DNA sample. The strategy follows a SARS-CoV-2 qPCR test in numerous ways. Students are provided isolated DNA representing a mock human patient sample, and determine if a viral genome (bacteriophage lambda) is present using qPCR. A battery of control samples and patient pooling strategies are utilized. The laboratory exercise is successful based on high rates of student success in detecting viral genomes, pre-quiz and post-quiz assessments focusing on viral qPCR testing, and positive student comments.
Collapse
Affiliation(s)
- Kevin T Militello
- Biology Department, State University of New York at Geneseo, Geneseo, New York, USA
| | - Hristina Nedelkovska
- Biology Department, State University of New York at Geneseo, Geneseo, New York, USA
| |
Collapse
|
16
|
Perez JG, Carlson ED, Weisser O, Kofman C, Seki K, Des Soye BJ, Karim AS, Jewett MC. Improving genomically recoded Escherichia coli to produce proteins containing non-canonical amino acids. Biotechnol J 2022; 17:e2100330. [PMID: 34894206 DOI: 10.1002/biot.202100330] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 12/08/2021] [Accepted: 12/09/2021] [Indexed: 12/12/2022]
Abstract
A genomically recoded Escherichia coli strain that lacks all amber codons and release factor 1 (C321.∆A) enables efficient genetic encoding of chemically diverse non-canonical amino acids (ncAAs) into proteins. While C321.∆A has opened new opportunities in chemical and synthetic biology, this strain has not been optimized for protein production, limiting its utility in widespread industrial and academic applications. To address this limitation, the construction of a series of genomically recoded organisms that are optimized for cellular protein production is described. It is demonstrated that the functional deactivation of nucleases (e.g., rne, endA) and proteases (e.g., lon) increases production of wild-type superfolder green fluorescent protein (sfGFP) and sfGFP containing two ncAAs up to ≈5-fold. Additionally, a genomic IPTG-inducible T7 RNA polymerase (T7RNAP) cassette into these strains is introduced. Using an optimized platform, the ability to introduce two identical N6 -(propargyloxycarbonyl)-L -Lysine residues site specifically into sfGFP with a 17-fold improvement in production relative to the parent strain is demonstrated. The authors envision that their library of organisms will provide the community with multiple options for increased expression of proteins with new and diverse chemistries.
Collapse
Affiliation(s)
- Jessica G Perez
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Erik D Carlson
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Oliver Weisser
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Camila Kofman
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Kosuke Seki
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Benjamin J Des Soye
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Ashty S Karim
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois, USA
- Simpson Querrey Institute, Northwestern University, Chicago, Illinois, USA
| |
Collapse
|
17
|
Budiardjo SJ, Stevens JJ, Calkins AL, Ikujuni AP, Wimalasena VK, Firlar E, Case DA, Biteen JS, Kaelber JT, Slusky JSG. Colicin E1 opens its hinge to plug TolC. eLife 2022; 11:73297. [PMID: 35199644 PMCID: PMC9020818 DOI: 10.7554/elife.73297] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 02/21/2022] [Indexed: 12/02/2022] Open
Abstract
The double membrane architecture of Gram-negative bacteria forms a barrier that is impermeable to most extracellular threats. Bacteriocin proteins evolved to exploit the accessible, surface-exposed proteins embedded in the outer membrane to deliver cytotoxic cargo. Colicin E1 is a bacteriocin produced by, and lethal to, Escherichia coli that hijacks the outer membrane proteins (OMPs) TolC and BtuB to enter the cell. Here, we capture the colicin E1 translocation domain inside its membrane receptor, TolC, by high-resolution cryo-electron microscopy to obtain the first reported structure of a bacteriocin bound to TolC. Colicin E1 binds stably to TolC as an open hinge through the TolC pore—an architectural rearrangement from colicin E1’s unbound conformation. This binding is stable in live E. coli cells as indicated by single-molecule fluorescence microscopy. Finally, colicin E1 fragments binding to TolC plug the channel, inhibiting its native efflux function as an antibiotic efflux pump, and heightening susceptibility to three antibiotic classes. In addition to demonstrating that these protein fragments are useful starting points for developing novel antibiotic potentiators, this method could be expanded to other colicins to inhibit other OMP functions. Bacteria are constantly warring with each other for space and resources. As a result, they have developed a range of molecular weapons to poison, damage or disable other cells. For instance, bacteriocins are proteins that can latch onto structures at the surface of enemy bacteria and push toxins through their outer membrane. Bacteria are increasingly resistant to antibiotics, representing a growing concern for modern healthcare. One way that they are able to survive is by using ‘efflux pumps’ studded through their external membranes to expel harmful drugs before these can cause damage. Budiardjo et al. wanted to test whether bacteriocins could interfere with this defence mechanism by blocking efflux pumps. Bacteriocins are usually formed of binding elements (which recognise specific target proteins) and of a ‘killer tail’ that can stab the cell. Experiments showed that the binding parts of a bacteriocin could effectively ‘plug’ efflux pumps in Escherichia coli bacteria: high-resolution molecular microscopy revealed how the bacteriocin fragment binds to the pump, while fluorescent markers showed that it attached to the surface of E. coli and stopped the efflux pumps from working. As a result, lower amounts of antibiotics were necessary to kill the bacteria when bacteriocins were present. The work by Budiardjo et al. could lead to new ways to combat bacteria that will reduce the need for current antibiotics. In the future, bacteriocins could also be harnessed to target other proteins than efflux pumps, allowing scientists to manipulate a range of bacterial processes.
Collapse
Affiliation(s)
- S Jimmy Budiardjo
- Center for Computational Biology, University of Kansas, Lawrence, United States
| | - Jacqueline J Stevens
- Department of Molecular Biosciences, University of Kansas, Lawrence, United States
| | - Anna L Calkins
- Department of Chemistry, University of Michigan, Ann Arbor, United States
| | - Ayotunde P Ikujuni
- Department of Molecular Biosciences, University of Kansas, Lawrence, United States
| | | | - Emre Firlar
- Institute for Quantitative Biomedicine, Rutgers University, Piscataway, United States
| | - David A Case
- Institute for Quantitative Biomedicine, Rutgers University, Piscataway, United States
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, United States
| | - Jason T Kaelber
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, United States
| | - Joanna S G Slusky
- Center for Computational Biology, University of Kansas, Lawrence, United States
| |
Collapse
|
18
|
Karyolaimos A, de Gier JW. Strategies to Enhance Periplasmic Recombinant Protein Production Yields in Escherichia coli. Front Bioeng Biotechnol 2021; 9:797334. [PMID: 34970535 PMCID: PMC8712718 DOI: 10.3389/fbioe.2021.797334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/24/2021] [Indexed: 11/29/2022] Open
Abstract
Main reasons to produce recombinant proteins in the periplasm of E. coli rather than in its cytoplasm are to -i- enable disulfide bond formation, -ii- facilitate protein isolation, -iii- control the nature of the N-terminus of the mature protein, and -iv- minimize exposure to cytoplasmic proteases. However, hampered protein targeting, translocation and folding as well as protein instability can all negatively affect periplasmic protein production yields. Strategies to enhance periplasmic protein production yields have focused on harmonizing secretory recombinant protein production rates with the capacity of the secretory apparatus by transcriptional and translational tuning, signal peptide selection and engineering, increasing the targeting, translocation and periplasmic folding capacity of the production host, preventing proteolysis, and, finally, the natural and engineered adaptation of the production host to periplasmic protein production. Here, we discuss these strategies using notable examples as a thread.
Collapse
Affiliation(s)
| | - Jan-Willem de Gier
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| |
Collapse
|
19
|
Heo JM, Kim HJ, Lee SJ. Efficient anaerobic consumption of D-xylose by E. coli BL21(DE3) via xylR adaptive mutation. BMC Microbiol 2021; 21:332. [PMID: 34872501 PMCID: PMC8647362 DOI: 10.1186/s12866-021-02395-9] [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: 03/30/2021] [Accepted: 11/22/2021] [Indexed: 11/20/2022] Open
Abstract
Background Microorganisms can prioritize the uptake of different sugars depending on their metabolic needs and preferences. When both D-glucose and D-xylose are present in growth media, E. coli cells typically consume D-glucose first and then D-xylose. Similarly, when E. coli BL21(DE3) is provided with both D-glucose and D-xylose under anaerobic conditions, glucose is consumed first, whereas D-xylose is consumed very slowly. Results When BL21(DE3) was adaptively evolved via subculture, the consumption rate of D-xylose increased gradually. Strains JH001 and JH019, whose D-xylose consumption rate was faster, were isolated after subculture. Genome analysis of the JH001 and JH019 strains revealed that C91A (Q31K) and C740T (A247V) missense mutations in the xylR gene (which encodes the XylR transcriptional activator), respectively, controlled the expression of the xyl operon. RT-qPCR analyses demonstrated that the XylR mutation caused a 10.9-fold and 3.5-fold increase in the expression of the xylA (xylose isomerase) and xylF (xylose transporter) genes, respectively, in the adaptively evolved JH001 and JH019 strains. A C91A adaptive mutation was introduced into a new BL21(DE3) background via single-base genome editing, resulting in immediate and efficient D-xylose consumption. Conclusions Anaerobically-adapted BL21(DE3) cells were obtained through short-term adaptive evolution and xylR mutations responsible for faster D-xylose consumption were identified, which may aid in the improvement of microbial fermentation technology. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02395-9.
Collapse
Affiliation(s)
- Jung Min Heo
- Department of Systems Biotechnology, Chung-Ang University, Anseong, 17546, Republic of Korea
| | - Hyun Ju Kim
- Department of Systems Biotechnology, Chung-Ang University, Anseong, 17546, Republic of Korea
| | - Sang Jun Lee
- Department of Systems Biotechnology, Chung-Ang University, Anseong, 17546, Republic of Korea.
| |
Collapse
|
20
|
Maffei E, Shaidullina A, Burkolter M, Heyer Y, Estermann F, Druelle V, Sauer P, Willi L, Michaelis S, Hilbi H, Thaler DS, Harms A. Systematic exploration of Escherichia coli phage-host interactions with the BASEL phage collection. PLoS Biol 2021; 19:e3001424. [PMID: 34784345 PMCID: PMC8594841 DOI: 10.1371/journal.pbio.3001424] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 09/27/2021] [Indexed: 01/08/2023] Open
Abstract
Bacteriophages, the viruses infecting bacteria, hold great potential for the treatment of multidrug-resistant bacterial infections and other applications due to their unparalleled diversity and recent breakthroughs in their genetic engineering. However, fundamental knowledge of the molecular mechanisms underlying phage-host interactions is mostly confined to a few traditional model systems and did not keep pace with the recent massive expansion of the field. The true potential of molecular biology encoded by these viruses has therefore remained largely untapped, and phages for therapy or other applications are often still selected empirically. We therefore sought to promote a systematic exploration of phage-host interactions by composing a well-assorted library of 68 newly isolated phages infecting the model organism Escherichia coli that we share with the community as the BASEL (BActeriophage SElection for your Laboratory) collection. This collection is largely representative of natural E. coli phage diversity and was intensively characterized phenotypically and genomically alongside 10 well-studied traditional model phages. We experimentally determined essential host receptors of all phages, quantified their sensitivity to 11 defense systems across different layers of bacterial immunity, and matched these results to the phages' host range across a panel of pathogenic enterobacterial strains. Clear patterns in the distribution of phage phenotypes and genomic features highlighted systematic differences in the potency of different immunity systems and suggested the molecular basis of receptor specificity in several phage groups. Our results also indicate strong trade-offs between fitness traits like broad host recognition and resistance to bacterial immunity that might drive the divergent adaptation of different phage groups to specific ecological niches. We envision that the BASEL collection will inspire future work exploring the biology of bacteriophages and their hosts by facilitating the discovery of underlying molecular mechanisms as the basis for an effective translation into biotechnology or therapeutic applications.
Collapse
Affiliation(s)
- Enea Maffei
- Biozentrum, University of Basel, Basel, Switzerland
| | | | | | - Yannik Heyer
- Biozentrum, University of Basel, Basel, Switzerland
| | | | | | | | - Luc Willi
- Biozentrum, University of Basel, Basel, Switzerland
| | - Sarah Michaelis
- Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
| | - Hubert Hilbi
- Institute of Medical Microbiology, University of Zürich, Zürich, Switzerland
| | - David S. Thaler
- Biozentrum, University of Basel, Basel, Switzerland
- Program for the Human Environment, Rockefeller University, New York City, New York, United States of America
| | | |
Collapse
|
21
|
Patenall BL, Hathaway HJ, Laabei M, Young AE, Thet NT, Jenkins ATA, Short RD, Allinson SL. Assessment of mutations induced by cold atmospheric plasma jet treatment relative to known mutagens in Escherichia coli. Mutagenesis 2021; 36:380-387. [PMID: 34459491 DOI: 10.1093/mutage/geab030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 08/29/2021] [Indexed: 11/12/2022] Open
Abstract
The main bactericidal components of cold atmospheric plasma (CAP) are thought to be reactive oxygen and nitrogen species (RONS) and UV-radiation, both of which have the capacity to cause DNA damage and mutations. Here, the mutagenic effects of CAP on Escherichia coli were assessed in comparison to X- and UV-irradiation. DNA damage and mutagenesis were screened for using a diffusion-based DNA fragmentation assay and modified Ames test, respectively. Mutant colonies obtained from the latter were quantitated and sequenced. CAP was found to elicit a similar mutation spectrum to X-irradiation, which did not resemble that for UV implying that CAP-produced RONS are more likely the mutagenic component of CAP. CAP treatment was also shown to promote resistance to the antibiotic ciprofloxacin. Our data suggest that CAP treatment has mutagenic effects that may have important phenotypic consequences.
Collapse
Affiliation(s)
| | - Hollie J Hathaway
- Department of Chemistry, Faculty of Science and Technology, Lancaster University, Lancaster, LA1 4YB, UK
| | - Maisem Laabei
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AX, UK
| | - Amber E Young
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, BS8 1UD, UK
| | - Naing T Thet
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | | | - Robert D Short
- Department of Chemistry, Faculty of Science and Technology, Lancaster University, Lancaster, LA1 4YB, UK
| | - Sarah L Allinson
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, LA1 4YG, UK
| |
Collapse
|
22
|
Hao N, Chen Q, Dodd IB, Shearwin KE. The pIT5 Plasmid Series, an Improved Toolkit for Repeated Genome Integration in E. coli. ACS Synth Biol 2021; 10:1633-1639. [PMID: 34190535 DOI: 10.1021/acssynbio.1c00215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe a new set of tools for inserting DNA into the bacterial chromosome. The system uses site-specific recombination reactions carried out by bacteriophage integrases to integrate plasmids at up to eight phage attachment sites in E. coli MG1655. The introduction of mutant loxP sites in the integrating plasmids allows repeated removal of antibiotic resistance genes and other plasmid sequences without danger of inducing chromosomal rearrangements. The protocol for Cre-mediated antibiotic resistance gene removal is greatly simplified by introducing the Cre plasmid by phage infection. Finally, we have also developed a set of four independently inducible expression modules with tight control and high dynamic range which can be inserted at specific chromosomal locations.
Collapse
Affiliation(s)
- Nan Hao
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
- CSIRO Synthetic Biology Future Science Platform, Canberra, ACT 2601, Australia
| | - Qinqin Chen
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Ian B. Dodd
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Keith E. Shearwin
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, SA 5005, Australia
| |
Collapse
|
23
|
Method for high-efficiency fed-batch cultures of recombinant Escherichia coli. Methods Enzymol 2021; 659:189-217. [PMID: 34752285 DOI: 10.1016/bs.mie.2021.05.004] [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: 01/04/2023]
Abstract
Fed-batch processes are commonly used in industry to obtain sufficient biomass and associated recombinant protein or plasmids. In research laboratories, it is more common to use batch cultures, as the setup of fed-batch processes can be challenging. This method outlines a robust and reliable means to generate Escherichia coli biomass in a minimum amount of fermentation time using a standardized fed-batch process. Final cell densities can reach over 50g dry cell weight per liter (gdcw/L) depending on the strain. This method uses a predefined exponential feeding strategy and conservative induction protocol to achieve these targets without multiple trial and error studies. If desired, productivity can be optimized by balancing the induction time and feed rates. This method utilizes cost-efficient defined media, minimizes process control complexity, and potentially aids downstream purification.
Collapse
|
24
|
Genomic evolution of antibiotic resistance is contingent on genetic background following a long-term experiment with Escherichia coli. Proc Natl Acad Sci U S A 2021; 118:2016886118. [PMID: 33441451 DOI: 10.1073/pnas.2016886118] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Antibiotic resistance is a growing health concern. Efforts to control resistance would benefit from an improved ability to forecast when and how it will evolve. Epistatic interactions between mutations can promote divergent evolutionary trajectories, which complicates our ability to predict evolution. We recently showed that differences between genetic backgrounds can lead to idiosyncratic responses in the evolvability of phenotypic resistance, even among closely related Escherichia coli strains. In this study, we examined whether a strain's genetic background also influences the genotypic evolution of resistance. Do lineages founded by different genotypes take parallel or divergent mutational paths to achieve their evolved resistance states? We addressed this question by sequencing the complete genomes of antibiotic-resistant clones that evolved from several different genetic starting points during our earlier experiments. We first validated our statistical approach by quantifying the specificity of genomic evolution with respect to antibiotic treatment. As expected, mutations in particular genes were strongly associated with each drug. Then, we determined that replicate lines evolved from the same founding genotypes had more parallel mutations at the gene level than lines evolved from different founding genotypes, although these effects were more subtle than those showing antibiotic specificity. Taken together with our previous work, we conclude that historical contingency can alter both genotypic and phenotypic pathways to antibiotic resistance.
Collapse
|
25
|
Hamouche L, Poljak L, Carpousis AJ. Ribosomal RNA degradation induced by the bacterial RNA polymerase inhibitor rifampicin. RNA (NEW YORK, N.Y.) 2021; 27:rna.078776.121. [PMID: 34099575 PMCID: PMC8284325 DOI: 10.1261/rna.078776.121] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/03/2021] [Indexed: 05/12/2023]
Abstract
Rifampicin, a broad-spectrum antibiotic, inhibits bacterial RNA polymerase. Here we show that rifampicin treatment of Escherichia coli results in a 50% decrease in cell size due to a terminal cell division. This decrease is a consequence of inhibition of transcription as evidenced by an isogenic rifampicin-resistant strain. There is also a 50% decrease in total RNA due mostly to a 90% decrease in 23S and 16S rRNA levels. Control experiments showed this decrease is not an artifact of our RNA purification protocol and therefore due to degradation in vivo. Since chromosome replication continues after rifampicin treatment, ribonucleotides from rRNA degradation could be recycled for DNA synthesis. Rifampicin-induced rRNA degradation occurs under different growth conditions and in different strain backgrounds. However, rRNA degradation is never complete thus permitting the re-initiation of growth after removal of rifampicin. The orderly shutdown of growth under conditions where the induction of stress genes is blocked by rifampicin is noteworthy. Inhibition of protein synthesis by chloramphenicol resulted in a partial decrease in 23S and 16S rRNA levels whereas kasugamycin treatment had no effect. Analysis of temperature-sensitive mutant strains implicate RNase E, PNPase and RNase R in rifampicin-induced rRNA degradation. We cannot distinguish between a direct role for RNase E in rRNA degradation versus an indirect role involving a slowdown of mRNA degradation. Since mRNA and rRNA appear to be degraded by the same ribonucleases, competition by rRNA is likely to result in slower mRNA degradation rates in the presence of rifampicin than under normal growth conditions.
Collapse
Affiliation(s)
- Lina Hamouche
- LMGM, CBI, Universite de Toulouse, CNRS, UPS, Toulouse, France
| | - Leonora Poljak
- LMGM, CBI, Universite de Toulouse, CNRS, UPS, Toulouse, France
| | | |
Collapse
|
26
|
Hwang Y, Kim SG, Jang S, Kim J, Jung GY. Signal amplification and optimization of riboswitch-based hybrid inputs by modular and titratable toehold switches. J Biol Eng 2021; 15:11. [PMID: 33741029 PMCID: PMC7977183 DOI: 10.1186/s13036-021-00261-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 03/03/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Synthetic biological circuits are widely utilized to control microbial cell functions. Natural and synthetic riboswitches are attractive sensor modules for use in synthetic biology applications. However, tuning the fold-change of riboswitch circuits is challenging because a deep understanding of the riboswitch mechanism and screening of mutant libraries is generally required. Therefore, novel molecular parts and strategies for straightforward tuning of the fold-change of riboswitch circuits are needed. RESULTS In this study, we devised a toehold switch-based modulator approach that combines a hybrid input construct consisting of a riboswitch and transcriptional repressor and de-novo-designed riboregulators named toehold switches. First, the introduction of a pair of toehold switches and triggers as a downstream signal-processing module to the hybrid input for coenzyme B12 resulted in a functional riboswitch circuit. Next, several optimization strategies that focused on balancing the expression levels of the RNA components greatly improved the fold-change from 260- to 887-fold depending on the promoter and host strain. Further characterizations confirmed low leakiness and high orthogonality of five toehold switch pairs, indicating the broad applicability of this strategy to riboswitch tuning. CONCLUSIONS The toehold switch-based modulator substantially improved the fold-change compared to the previous sensors with only the hybrid input construct. The programmable RNA-RNA interactions amenable to in silico design and optimization can facilitate further development of RNA-based genetic modulators for flexible tuning of riboswitch circuitry and synthetic biosensors.
Collapse
Affiliation(s)
- Yunhee Hwang
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Seong Gyeong Kim
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Sungho Jang
- Department of Bioengineering and Nano-Bioengineering, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon, 22012, South Korea
- Division of Bioengineering, College of Life Sciences and Bioengineering, Incheon National University, 119 Academy-ro, Yeonsu-gu, Incheon, 22012, South Korea
| | - Jongmin Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673, South Korea.
| | - Gyoo Yeol Jung
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673, South Korea.
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk, 37673, South Korea.
| |
Collapse
|
27
|
Insertion-sequence-mediated mutations both promote and constrain evolvability during a long-term experiment with bacteria. Nat Commun 2021; 12:980. [PMID: 33579917 PMCID: PMC7881107 DOI: 10.1038/s41467-021-21210-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 01/08/2021] [Indexed: 01/26/2023] Open
Abstract
Insertion sequences (IS) are ubiquitous bacterial mobile genetic elements, and the mutations they cause can be deleterious, neutral, or beneficial. The long-term dynamics of IS elements and their effects on bacteria are poorly understood, including whether they are primarily genomic parasites or important drivers of adaptation by natural selection. Here, we investigate the dynamics of IS elements and their contribution to genomic evolution and fitness during a long-term experiment with Escherichia coli. IS elements account for ~35% of the mutations that reached high frequency through 50,000 generations in those populations that retained the ancestral point-mutation rate. In mutator populations, IS-mediated mutations are only half as frequent in absolute numbers. In one population, an exceptionally high ~8-fold increase in IS150 copy number is associated with the beneficial effects of early insertion mutations; however, this expansion later slowed down owing to reduced IS150 activity. This population also achieves the lowest fitness, suggesting that some avenues for further adaptation are precluded by the IS150-mediated mutations. More generally, across all populations, we find that higher IS activity becomes detrimental to adaptation over evolutionary time. Therefore, IS-mediated mutations can both promote and constrain evolvability. Insertion sequences (IS) are common mobile genetic elements in bacteria, but their effects on bacterial evolution are not well understood. Here, Consuegra and colleagues investigate the dynamics and fitness consequences of IS elements in E. coli over 50,000 generations.
Collapse
|
28
|
Gifford I, Dasgupta A, Barrick JE. Rates of gene conversions between Escherichia coli ribosomal operons. G3-GENES GENOMES GENETICS 2021; 11:5974039. [PMID: 33585862 PMCID: PMC8022953 DOI: 10.1093/g3journal/jkaa002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/10/2020] [Indexed: 11/23/2022]
Abstract
Due to their universal presence and high sequence conservation, ribosomal RNA (rRNA) sequences are used widely in phylogenetics for inferring evolutionary relationships between microbes and in metagenomics for analyzing the composition of microbial communities. Most microbial genomes encode multiple copies of rRNA genes to supply cells with sufficient capacity for protein synthesis. These copies typically undergo concerted evolution that keeps their sequences identical, or nearly so, due to gene conversion, a type of intragenomic recombination that changes one copy of a homologous sequence to exactly match another. Widely varying rates of rRNA gene conversion have previously been estimated by comparative genomics methods and using genetic reporter assays. To more directly measure rates of rRNA intragenomic recombination, we sequenced the seven Escherichia coli rRNA operons in 15 lineages that were evolved for ∼13,750 generations with frequent single-cell bottlenecks that reduce the effects of selection. We identified 38 gene conversion events and estimated an overall rate of intragenomic recombination within the 16S and 23S genes between rRNA copies of 3.6 × 10−4 per genome per generation or 8.6 × 10−6 per rRNA operon per homologous donor operon per generation. This rate varied only slightly from random expectations at different sites within the rRNA genes and between rRNA operons located at different positions in the genome. Our accurate estimate of the rate of rRNA gene conversions fills a gap in our quantitative understanding of how ribosomal sequences and other multicopy elements diversify and homogenize during microbial genome evolution.
Collapse
Affiliation(s)
- Isaac Gifford
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Aurko Dasgupta
- 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
| |
Collapse
|
29
|
Wannier TM, Ciaccia PN, Ellington AD, Filsinger GT, Isaacs FJ, Javanmardi K, Jones MA, Kunjapur AM, Nyerges A, Pal C, Schubert MG, Church GM. Recombineering and MAGE. NATURE REVIEWS. METHODS PRIMERS 2021; 1:7. [PMID: 35540496 PMCID: PMC9083505 DOI: 10.1038/s43586-020-00006-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/19/2020] [Indexed: 12/17/2022]
Abstract
Recombination-mediated genetic engineering, also known as recombineering, is the genomic incorporation of homologous single-stranded or double-stranded DNA into bacterial genomes. Recombineering and its derivative methods have radically improved genome engineering capabilities, perhaps none more so than multiplex automated genome engineering (MAGE). MAGE is representative of a set of highly multiplexed single-stranded DNA-mediated technologies. First described in Escherichia coli, both MAGE and recombineering are being rapidly translated into diverse prokaryotes and even into eukaryotic cells. Together, this modern set of tools offers the promise of radically improving the scope and throughput of experimental biology by providing powerful new methods to ease the genetic manipulation of model and non-model organisms. In this Primer, we describe recombineering and MAGE, their optimal use, their diverse applications and methods for pairing them with other genetic editing tools. We then look forward to the future of genetic engineering.
Collapse
Affiliation(s)
- Timothy M. Wannier
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Peter N. Ciaccia
- Department of Molecular, Cellular & Developmental Biology, Yale University, New Haven, CT, USA
- Systems Biology Institute, Yale University, West Haven, CT, USA
| | - Andrew D. Ellington
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX, USA
| | - Gabriel T. Filsinger
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
- Department of Systems Biology, Harvard University, Cambridge, MA, USA
| | - Farren J. Isaacs
- Department of Molecular, Cellular & Developmental Biology, Yale University, New Haven, CT, USA
- Systems Biology Institute, Yale University, West Haven, CT, USA
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Kamyab Javanmardi
- Department of Molecular Biosciences, College of Natural Sciences, University of Texas at Austin, Austin, TX, USA
| | - Michaela A. Jones
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA
| | - Aditya M. Kunjapur
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA
| | - Akos Nyerges
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Csaba Pal
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Max G. Schubert
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - George M. Church
- Department of Genetics, Harvard Medical School, Boston, MA, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| |
Collapse
|
30
|
James J, Yarnall B, Koranteng A, Gibson J, Rahman T, Doyle DA. Protein over-expression in Escherichia coli triggers adaptation analogous to antimicrobial resistance. Microb Cell Fact 2021; 20:13. [PMID: 33430875 PMCID: PMC7798265 DOI: 10.1186/s12934-020-01462-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 10/27/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The E. coli pET system is the most widely used protein over-expression system worldwide. It relies on the assumption that all cells produce target protein and it is generally believed that integral membrane protein (IMP) over-expression is more toxic than their soluble counterparts. RESULTS Using GFP-tagged proteins, high level over-expression of either soluble or IMP targets results in > 99.9% cell loss with survival rate of only < 0.03%. Selective pressure generates three phenotypes: large green, large white and small colony variants. As a result, in overnight cultures, ~ 50% of the overall cell mass produces no protein. Genome sequencing of the phenotypes revealed genomic mutations that causes either the loss of T7 RNAP activity or its transcriptional downregulation. The over-expression process is bactericidal and is observed for both soluble and membrane proteins. CONCLUSIONS We demonstrate that it is the act of high-level over-expression of exogenous proteins in E. coli that sets in motion a chain of events leading to > 99.9% cell death. These results redefine our understanding of protein over-production and link it to the adaptive survival response seen in the development of antimicrobial resistance.
Collapse
Affiliation(s)
- Jack James
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Benjamin Yarnall
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Andy Koranteng
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Jane Gibson
- Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK
| | - Tahmina Rahman
- Queen Alexandra Hospital, Portsmouth Hospital University NHS Trust, Cosham, Portsmouth, PO6 3LY, UK
| | - Declan A Doyle
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK.
| |
Collapse
|
31
|
Misincorporation of Galactose by Chondroitin Synthase of Escherichia coli K4: From Traces to Synthesis of Chondbiuronan, a Novel Chondroitin-Like Polysaccharide. Biomolecules 2020; 10:biom10121667. [PMID: 33322778 PMCID: PMC7764085 DOI: 10.3390/biom10121667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 11/29/2022] Open
Abstract
Chondroitin synthase KfoC is a bifunctional enzyme which polymerizes the capsular chondroitin backbone of Escherichia coli K4, composed of repeated β3N-acetylgalactosamine (GalNAc)-β4-glucuronic acid (GlcA) units. Sugar donors UDP-GalNAc and UDP-GlcA are the natural precursors of bacterial chondroitin synthesis. We have expressed KfoC in a recombinant strain of Escherichia coli deprived of 4-epimerase activity, thus incapable of supplying UDP-GalNAc in the bacterial cytoplasm. The strain was also co-expressing mammal galactose β-glucuronyltransferase, providing glucuronyl-lactose from exogenously added lactose, serving as a primer of polymerization. We show by the mean of NMR analyses that in those conditions, KfoC incorporates galactose, forming a chondroitin-like polymer composed of the repeated β3-galactose (Gal)-β4-glucuronic acid units. We also show that when UDP-GlcNAc 4-epimerase KfoA, encoded by the K4-operon, was co-expressed and produced UDP-GalNAc, a small proportion of galactose was still incorporated into the growing chain of chondroitin.
Collapse
|
32
|
Gurung D, Blumenthal RM. Distribution of RecBCD and AddAB recombination-associated genes among bacteria in 33 phyla. MICROBIOLOGY-SGM 2020; 166:1047-1064. [PMID: 33085588 DOI: 10.1099/mic.0.000980] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Homologous recombination plays key roles in fundamental processes such as recovery from DNA damage and in bacterial horizontal gene transfer, yet there are still open questions about the distribution of recognized components of recombination machinery among bacteria and archaea. RecBCD helicase-nuclease plays a central role in recombination among Gammaproteobacteria like Escherichia coli; while bacteria in other phyla, like the Firmicute Bacillus subtilis, use the related AddAB complex. The activity of at least some of these complexes is controlled by short DNA sequences called crossover hotspot instigator (Chi) sites. When RecBCD or AddAB complexes encounter an autologous Chi site during unwinding, they introduce a nick such that ssDNA with a free end is available to invade another duplex. If homologous DNA is present, RecA-dependent homologous recombination is promoted; if not (or if no autologous Chi site is present) the RecBCD/AddAB complex eventually degrades the DNA. We examined the distribution of recBCD and addAB genes among bacteria, and sought ways to distinguish them unambiguously. We examined bacterial species among 33 phyla, finding some unexpected distribution patterns. RecBCD and addAB are less conserved than recA, with the orthologous recB and addA genes more conserved than the recC or addB genes. We were able to classify RecB vs. AddA and RecC vs. AddB in some bacteria where this had not previously been done. We used logo analysis to identify sequence segments that are conserved, but differ between the RecBC and AddAB proteins, to help future differentiation between members of these two families.
Collapse
Affiliation(s)
- Deepti Gurung
- Present address: Department of Cancer Biology, College of Medicine & Life Sciences, The University of Toledo, Toledo OH 43614-1021, USA.,Department of Medical Microbiology & Immunology, and Program in Bioinformatics, College of Medicine & Life Sciences, The University of Toledo, Toledo OH 43614-1021, USA
| | - Robert M Blumenthal
- Department of Medical Microbiology & Immunology, and Program in Bioinformatics, College of Medicine & Life Sciences, The University of Toledo, Toledo OH 43614-1021, USA
| |
Collapse
|
33
|
Atolia E, Cesar S, Arjes HA, Rajendram M, Shi H, Knapp BD, Khare S, Aranda-Díaz A, Lenski RE, Huang KC. Environmental and Physiological Factors Affecting High-Throughput Measurements of Bacterial Growth. mBio 2020; 11:e01378-20. [PMID: 33082255 PMCID: PMC7587430 DOI: 10.1128/mbio.01378-20] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/10/2020] [Indexed: 11/20/2022] Open
Abstract
Bacterial growth under nutrient-rich and starvation conditions is intrinsically tied to the environmental history and physiological state of the population. While high-throughput technologies have enabled rapid analyses of mutant libraries, technical and biological challenges complicate data collection and interpretation. Here, we present a framework for the execution and analysis of growth measurements with improved accuracy over that of standard approaches. Using this framework, we demonstrate key biological insights that emerge from consideration of culturing conditions and history. We determined that quantification of the background absorbance in each well of a multiwell plate is critical for accurate measurements of maximal growth rate. Using mathematical modeling, we demonstrated that maximal growth rate is dependent on initial cell density, which distorts comparisons across strains with variable lag properties. We established a multiple-passage protocol that alleviates the substantial effects of glycerol on growth in carbon-poor media, and we tracked growth rate-mediated fitness increases observed during a long-term evolution of Escherichia coli in low glucose concentrations. Finally, we showed that growth of Bacillus subtilis in the presence of glycerol induces a long lag in the next passage due to inhibition of a large fraction of the population. Transposon mutagenesis linked this phenotype to the incorporation of glycerol into lipoteichoic acids, revealing a new role for these envelope components in resuming growth after starvation. Together, our investigations underscore the complex physiology of bacteria during bulk passaging and the importance of robust strategies to understand and quantify growth.IMPORTANCE How starved bacteria adapt and multiply under replete nutrient conditions is intimately linked to their history of previous growth, their physiological state, and the surrounding environment. While automated equipment has enabled high-throughput growth measurements, data interpretation and knowledge gaps regarding the determinants of growth kinetics complicate comparisons between strains. Here, we present a framework for growth measurements that improves accuracy and attenuates the effects of growth history. We determined that background absorbance quantification and multiple passaging cycles allow for accurate growth rate measurements even in carbon-poor media, which we used to reveal growth-rate increases during long-term laboratory evolution of Escherichia coli Using mathematical modeling, we showed that maximum growth rate depends on initial cell density. Finally, we demonstrated that growth of Bacillus subtilis with glycerol inhibits the future growth of most of the population, due to lipoteichoic acid synthesis. These studies highlight the challenges of accurate quantification of bacterial growth behaviors.
Collapse
Affiliation(s)
- Esha Atolia
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, California, USA
| | - Spencer Cesar
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
| | - Heidi A Arjes
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Manohary Rajendram
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Handuo Shi
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Benjamin D Knapp
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA
| | - Somya Khare
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Andrés Aranda-Díaz
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Richard E Lenski
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
- BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, USA
| | - Kerwyn Casey Huang
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
- Department of Bioengineering, Stanford University, Stanford, California, USA
- Biophysics Program, Stanford University School of Medicine, Stanford, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
| |
Collapse
|
34
|
Combinatorial strategy towards the efficient expression of lipoxygenase in Escherichia coli at elevated temperatures. Appl Microbiol Biotechnol 2020; 104:10047-10057. [PMID: 33037915 DOI: 10.1007/s00253-020-10941-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 08/31/2020] [Accepted: 10/04/2020] [Indexed: 02/07/2023]
Abstract
Lipoxygenases (LOXs) are a family of non-heme iron oxidoreductases, which catalyze the addition of oxygen into polyunsaturated fatty acids. They have applications in the food and medical industries. In most studies, the soluble expression of LOXs in microbes requires low temperature (< 20 °C), which increases the cost and fermentation time. Achievement of soluble expression in elevated temperatures (> 30 °C) would shorten the production phase, leading to cost-efficient industrial applications. In this study, a combinatorial strategy was used to enhance the expression of soluble LOXs, comprising plasmid stability systems plus optimized carbon source used for auto-induction expression. Plasmid stability analysis suggested that both active partition systems and plasmid-dependent systems were essential for plasmid stability. Among them, the parBCA in it resulted in the enzyme activity increasing by a factor of 2 (498 ± 13 units per gram dry cell weight (U/g-DCW) after 6-h induction). Furthermore, the optimized carbon source, composed of glucose, lactose, and glycerol, could be used as an auto-induction expression medium and effectively improve the total and soluble expression of LOX, which resulted in the soluble expression of LOX increased by 7 times. Finally, the soluble expression of LOX was 11 times higher with a combinatorial strategy that included both optimized plasmid partition and auto-induction medium. Our work provides a broad, generalizable, and combinatorial strategy for the efficient production of heterologous proteins at elevated temperatures in the E. coli system. KEY POINTS : • Soluble expression of lipoxygenase at 30 °C or higher temperatures is industrially beneficial. • Strategies comprise plasmid partition and optimized auto-induction medium with glucose, lactose, and glycerol as carbon source. • Combinatorial strategy further improved LOX soluble expression at 30 °C and 37 °C.
Collapse
|
35
|
Mutalik VK, Adler BA, Rishi HS, Piya D, Zhong C, Koskella B, Kutter EM, Calendar R, Novichkov PS, Price MN, Deutschbauer AM, Arkin AP. High-throughput mapping of the phage resistance landscape in E. coli. PLoS Biol 2020; 18:e3000877. [PMID: 33048924 PMCID: PMC7553319 DOI: 10.1371/journal.pbio.3000877] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 09/08/2020] [Indexed: 12/18/2022] Open
Abstract
Bacteriophages (phages) are critical players in the dynamics and function of microbial communities and drive processes as diverse as global biogeochemical cycles and human health. Phages tend to be predators finely tuned to attack specific hosts, even down to the strain level, which in turn defend themselves using an array of mechanisms. However, to date, efforts to rapidly and comprehensively identify bacterial host factors important in phage infection and resistance have yet to be fully realized. Here, we globally map the host genetic determinants involved in resistance to 14 phylogenetically diverse double-stranded DNA phages using two model Escherichia coli strains (K-12 and BL21) with known sequence divergence to demonstrate strain-specific differences. Using genome-wide loss-of-function and gain-of-function genetic technologies, we are able to confirm previously described phage receptors as well as uncover a number of previously unknown host factors that confer resistance to one or more of these phages. We uncover differences in resistance factors that strongly align with the susceptibility of K-12 and BL21 to specific phage. We also identify both phage-specific mechanisms, such as the unexpected role of cyclic-di-GMP in host sensitivity to phage N4, and more generic defenses, such as the overproduction of colanic acid capsular polysaccharide that defends against a wide array of phages. Our results indicate that host responses to phages can occur via diverse cellular mechanisms. Our systematic and high-throughput genetic workflow to characterize phage-host interaction determinants can be extended to diverse bacteria to generate datasets that allow predictive models of how phage-mediated selection will shape bacterial phenotype and evolution. The results of this study and future efforts to map the phage resistance landscape will lead to new insights into the coevolution of hosts and their phage, which can ultimately be used to design better phage therapeutic treatments and tools for precision microbiome engineering.
Collapse
Affiliation(s)
- Vivek K. Mutalik
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Innovative Genomics Institute, Berkeley, California, United States of America
| | - Benjamin A. Adler
- Innovative Genomics Institute, Berkeley, California, United States of America
- Department of Bioengineering, University of California – Berkeley, Berkeley, California, United States of America
| | - Harneet S. Rishi
- Biophysics Graduate Group, University of California – Berkeley, Berkeley, California, United States of America
- Designated Emphasis Program in Computational and Genomic Biology, University of California – Berkeley, Berkeley, California, United States of America
| | - Denish Piya
- Innovative Genomics Institute, Berkeley, California, United States of America
- Department of Bioengineering, University of California – Berkeley, Berkeley, California, United States of America
| | - Crystal Zhong
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Britt Koskella
- Department of Integrative Biology, University of California – Berkeley, Berkeley, California, United States of America
| | | | - Richard Calendar
- Department of Molecular and Cell Biology, University of California – Berkeley, Berkeley, California, United States of America
| | - Pavel S. Novichkov
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Morgan N. Price
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
| | - Adam M. Deutschbauer
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Innovative Genomics Institute, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California – Berkeley, Berkeley, California, United States of America
| | - Adam P. Arkin
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Innovative Genomics Institute, Berkeley, California, United States of America
- Department of Bioengineering, University of California – Berkeley, Berkeley, California, United States of America
- Biophysics Graduate Group, University of California – Berkeley, Berkeley, California, United States of America
- Designated Emphasis Program in Computational and Genomic Biology, University of California – Berkeley, Berkeley, California, United States of America
| |
Collapse
|
36
|
Sun G, Hu C, Mei Q, Luo M, Chen X, Li Z, Liu Y, Deng Z, Zhang Z, Sun Y. Uncovering the cytochrome P450-catalyzed methylenedioxy bridge formation in streptovaricins biosynthesis. Nat Commun 2020; 11:4501. [PMID: 32908132 PMCID: PMC7481197 DOI: 10.1038/s41467-020-18336-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 08/18/2020] [Indexed: 12/14/2022] Open
Abstract
Streptovaricin C is a naphthalenic ansamycin antibiotic structurally similar to rifamycins with potential anti-MRSA bioactivities. However, the formation mechanism of the most fascinating and bioactivity-related methylenedioxy bridge (MDB) moiety in streptovaricins is unclear. Based on genetic and biochemical evidences, we herein clarify that the P450 enzyme StvP2 catalyzes the MDB formation in streptovaricins, with an atypical substrate inhibition kinetics. Furthermore, X-ray crystal structures in complex with substrate and structure-based mutagenesis reveal the intrinsic details of the enzymatic reaction. The mechanism of MDB formation is proposed to be an intramolecular nucleophilic substitution resulting from the hydroxylation by the heme core and the keto-enol tautomerization via a crucial catalytic triad (Asp89-His92-Arg72) in StvP2. In addition, in vitro reconstitution uncovers that C6-O-methylation and C4-O-acetylation of streptovaricins are necessary prerequisites for the MDB formation. This work provides insight for the MDB formation and adds evidence in support of the functional versatility of P450 enzymes. Streptovaricin C is an antibiotic containing a methylenedioxy bridge (MDB) moiety essential for its activity. Here, the authors show that a P450 monooxygenase StvP2 catalyses MDB formation, report its crystal structure in complex with the substrate, and elucidate mechanistic details of MDB formation.
Collapse
Affiliation(s)
- Guo Sun
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China
| | - Chaoqun Hu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China
| | - Qing Mei
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China
| | - Minghe Luo
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China
| | - Xu Chen
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China
| | - Zhengyuan Li
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China
| | - Yuanzhen Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China
| | - Zixin Deng
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China
| | - Zhengyu Zhang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China.
| | - Yuhui Sun
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, Wuhan University School of Pharmaceutical Sciences, 430071, Wuhan, P. R. China.
| |
Collapse
|
37
|
Udaondo Z, Duque E, Daddaoua A, Caselles C, Roca A, Pizarro-Tobias P, Ramos JL. Developing robust protein analysis profiles to identify bacterial acid phosphatases in genomes and metagenomic libraries. Environ Microbiol 2020; 22:3561-3571. [PMID: 32564477 DOI: 10.1111/1462-2920.15138] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 06/19/2020] [Indexed: 12/16/2022]
Abstract
Phylogenetic analysis of more than 4000 annotated bacterial acid phosphatases was carried out. Our analysis enabled us to sort these enzymes into the following three types: (1) class B acid phosphatases, which were distantly related to the other types, (2) class C acid phosphatases and (3) generic acid phosphatases (GAP). Although class B phosphatases are found in a limited number of bacterial families, which include known pathogens, class C acid phosphatases and GAP proteins are found in a variety of microbes that inhabit soil, fresh water and marine environments. As part of our analysis, we developed three profiles, named Pfr-B-Phos, Pfr-C-Phos and Pfr-GAP, to describe the three groups of acid phosphatases. These sequence-based profiles were then used to scan genomes and metagenomes to identify a large number of formerly unknown acid phosphatases. A number of proteins in databases annotated as hypothetical proteins were also identified by these profiles as putative acid phosphatases. To validate these in silico results, we cloned genes encoding candidate acid phosphatases from genomic DNA or recovered from metagenomic libraries or genes synthesized in vitro based on protein sequences recovered from metagenomic data. Expression of a number of these genes, followed by enzymatic analysis of the proteins, further confirmed that sequence similarity searches using our profiles could successfully identify previously unknown acid phosphatases.
Collapse
Affiliation(s)
- Zulema Udaondo
- Estación Experimental del Zaidín, CSIC, Granada, E-18008, Spain.,Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205, USA
| | - Estrella Duque
- Estación Experimental del Zaidín, CSIC, Granada, E-18008, Spain
| | - Abdelali Daddaoua
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Carlos Caselles
- Estación Experimental del Zaidín, CSIC, Granada, E-18008, Spain
| | | | | | - Juan L Ramos
- Estación Experimental del Zaidín, CSIC, Granada, E-18008, Spain
| |
Collapse
|
38
|
Kim H, Kim S, Kim D, Yoon SH. A single amino acid substitution in aromatic hydroxylase (HpaB) of Escherichia coli alters substrate specificity of the structural isomers of hydroxyphenylacetate. BMC Microbiol 2020; 20:109. [PMID: 32375644 PMCID: PMC7201708 DOI: 10.1186/s12866-020-01798-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 04/22/2020] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND A broad range of aromatic compounds can be degraded by enteric bacteria, and hydroxyphenylacetic acid (HPA) degrading bacteria are the most widespread. Majority of Escherichia coli strains can use both the structural isomers of HPA, 3HPA and 4HPA, as the sole carbon source, which are catabolized by the same pathway whose associated enzymes are encoded by hpa gene cluster. Previously, we observed that E. coli B REL606 grew only on 4HPA, while E. coli B BL21(DE3) grew on 3HPA as well as 4HPA. RESULTS In this study, we report that a single amino acid in 4-hydroxyphenylacetate 3-hydroxylase (HpaB) of E. coli determines the substrate specificity of HPA isomers. Alignment of protein sequences encoded in hpa gene clusters of BL21(DE3) and REL606 showed that there was a difference of only one amino acid (position 379 in HpaB) between the two, viz., Arg in BL21(DE3) and Cys in REL606. REL606 cells expressing HpaB having Arg379 could grow on 3HPA, whereas those expressing HpaB with Gly379 or Ser379 could not. Structural analysis suggested that the amino acid residue at position 379 of HpaB is located not in the active site, but in the vicinity of the 4HPA binding site, and that it plays an important role in mediating the entrance and stable binding of substrates to the active site. CONCLUSIONS The arginine residue at position 379 of HpaB is critical for 3HPA recognition. Information regarding the effect of amino acid residues on the substrate specificity of structural isomers can facilitate in designing hydoxylases with high catalytic efficiency and versatility.
Collapse
Affiliation(s)
- Hanseol Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Sinyeon Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Dohyeon Kim
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea
| | - Sung Ho Yoon
- Department of Bioscience and Biotechnology, Konkuk University, Seoul, 05029, Republic of Korea.
| |
Collapse
|
39
|
Pilak P, Schiefner A, Seiboth J, Oehrlein J, Skerra A. Engineering a Highly Active Sucrose Isomerase for Enhanced Product Specificity by Using a "Battleship" Strategy. Chembiochem 2020; 21:2161-2169. [PMID: 32181549 PMCID: PMC7496859 DOI: 10.1002/cbic.202000007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/09/2020] [Indexed: 11/19/2022]
Abstract
The sucrose isomerase SmuA from Serratia plymuthica efficiently catalyses the isomerisation of sucrose into isomaltulose, an artificial sweetener used in the food industry. However, the formation of a hygroscopic by‐product, trehalulose, necessitates additional separation to obtain a crystalline product. Therefore, we have improved the product specificity of SmuA by first introducing a few exploratory amino acid exchanges around the active site and investigating their influence. Then, we devised a second set of mutations, either at promising positions from the preceding cycle, but with a different side chain, or at alternative positions in the vicinity. After seven iterative cycles involving just 55 point mutations, we obtained the triple mutant Y219L/D398G/V465E which showed 2.3 times less trehalulose production but still had high catalytic efficiency (kcat/KM=11.8 mM−1 s−1). Not only does this mutant SmuA appear attractive as an industrial biocatalyst, but our semirational protein‐engineering strategy, which resembles the battleship board game, should be of interest for other challenging enzyme optimization endeavours.
Collapse
Affiliation(s)
- Patrick Pilak
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354, Freising, Germany
| | - André Schiefner
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354, Freising, Germany
| | - Judith Seiboth
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354, Freising, Germany
| | | | - Arne Skerra
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354, Freising, Germany
| |
Collapse
|
40
|
Noh MH, Lim HG, Moon D, Park S, Jung GY. Auxotrophic Selection Strategy for Improved Production of Coenzyme B 12 in Escherichia coli. iScience 2020; 23:100890. [PMID: 32086013 PMCID: PMC7033360 DOI: 10.1016/j.isci.2020.100890] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/17/2020] [Accepted: 02/03/2020] [Indexed: 02/02/2023] Open
Abstract
The production of coenzyme B12 using well-characterized microorganisms, such as Escherichia coli, has recently attracted considerable attention to meet growing demands of coenzyme B12 in various applications. In the present study, we designed an auxotrophic selection strategy and demonstrated the enhanced production of coenzyme B12 using a previously engineered coenzyme B12-producing E. coli strain. To select a high producer, the coenzyme B12-independent methionine synthase (metE) gene was deleted in E. coli, thus limiting its methionine synthesis to only that via coenzyme B12-dependent synthase (encoded by metH). Following the deletion of metE, significantly enhanced production of the specific coenzyme B12 validated the coenzyme B12-dependent auxotrophic growth. Further precise tuning of the auxotrophic system by varying the expression of metH substantially increased the cell biomass and coenzyme B12 production, suggesting that our strategy could be effectively applied to E. coli and other coenzyme B12-producing strains. The auxotrophic selection strategy was applied to coenzyme B12 production Coenzyme B12-independent methionine synthase was deleted for auxotroph system The auxotrophic strategy could significantly enhance the coenzyme B12 production Optimization of the auxotroph system further enhanced the coenzyme B12 production
Collapse
Affiliation(s)
- Myung Hyun Noh
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongsangbuk-do 37673, Korea
| | - Hyun Gyu Lim
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongsangbuk-do 37673, Korea
| | - Daeyeong Moon
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongsangbuk-do 37673, Korea
| | - Sunghoon Park
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, 50 UNIST-Ro, Ulju-gun, Ulsan, Korea
| | - Gyoo Yeol Jung
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongsangbuk-do 37673, Korea; School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongsangbuk-do 37673, Korea.
| |
Collapse
|
41
|
Elevated Expression of a Functional Suf Pathway in Escherichia coli BL21(DE3) Enhances Recombinant Production of an Iron-Sulfur Cluster-Containing Protein. J Bacteriol 2020; 202:JB.00496-19. [PMID: 31712282 DOI: 10.1128/jb.00496-19] [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: 07/26/2019] [Accepted: 11/07/2019] [Indexed: 01/09/2023] Open
Abstract
Structural and spectroscopic analysis of iron-sulfur [Fe-S] cluster-containing proteins is often limited by the occupancy and yield of recombinantly produced proteins. Here we report that Escherichia coli BL21(DE3), a strain routinely used to overproduce [Fe-S] cluster-containing proteins, has a nonfunctional Suf pathway, one of two E. coli [Fe-S] cluster biogenesis pathways. We confirmed that BL21(DE3) and commercially available derivatives carry a deletion that results in an in-frame fusion of sufA and sufB genes within the sufABCDSE operon. We show that this fusion protein accumulates in cells but is inactive in [Fe-S] cluster biogenesis. Restoration of an intact Suf pathway combined with enhanced suf operon expression led to a remarkable (∼3-fold) increase in the production of the [4Fe-4S] cluster-containing BchL protein, a key component of the dark-operative protochlorophyllide oxidoreductase complex. These results show that this engineered "SufFeScient" derivative of BL21(DE3) is suitable for enhanced large-scale synthesis of an [Fe-S] cluster-containing protein.IMPORTANCE Large quantities of recombinantly overproduced [Fe-S] cluster-containing proteins are necessary for their in-depth biochemical characterization. Commercially available E. coli strain BL21(DE3) and its derivatives have a mutation that inactivates the function of one of the two native pathways (Suf pathway) responsible for cluster biogenesis. Correction of the mutation, combined with sequence changes that elevate Suf protein levels, can increase yield and cluster occupancy of [Fe-S] cluster-containing enzymes, facilitating the biochemical analysis of this fascinating group of proteins.
Collapse
|
42
|
McKinlay JB, Cook GM, Hards K. Microbial energy management-A product of three broad tradeoffs. Adv Microb Physiol 2020; 77:139-185. [PMID: 34756210 DOI: 10.1016/bs.ampbs.2020.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Wherever thermodynamics allows, microbial life has evolved to transform and harness energy. Microbial life thus abounds in the most unexpected places, enabled by profound metabolic diversity. Within this diversity, energy is transformed primarily through variations on a few core mechanisms. Energy is further managed by the physiological processes of cell growth and maintenance that use energy. Some aspects of microbial physiology are streamlined for energetic efficiency while other aspects seem suboptimal or even wasteful. We propose that the energy that a microbe harnesses and devotes to growth and maintenance is a product of three broad tradeoffs: (i) economic, trading enzyme synthesis or operational cost for functional benefit, (ii) environmental, trading optimization for a single environment for adaptability to multiple environments, and (iii) thermodynamic, trading energetic yield for forward metabolic flux. Consideration of these tradeoffs allows one to reconcile features of microbial physiology that seem to opposingly promote either energetic efficiency or waste.
Collapse
Affiliation(s)
- James B McKinlay
- Department of Biology, Indiana University, Bloomington, IN, United States.
| | - Gregory M Cook
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| | - Kiel Hards
- Department of Microbiology and Immunology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, Auckland, New Zealand
| |
Collapse
|
43
|
Mitarai N. How pirate phage interferes with helper phage: Comparison of the two distinct strategies. J Theor Biol 2019; 486:110096. [PMID: 31786182 DOI: 10.1016/j.jtbi.2019.110096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 11/26/2022]
Abstract
Pirate phages use the structural proteins encoded by unrelated helper phages to propagate. The best-studied example is the pirate P4 and helper P2 of coliphages, and it has been known that the Staphylococcus aureus pathogenicity islands (SaPIs) that can encode virulence factors act as pirate phages, too. When alone in the host, the pirate phages act as a prophage, but when the helper phage gene is also in the same host cell, the pirate phage has ability to exploit the helper phages structural proteins to produce pirate phage particles and spread, interfering with the helper phage production. The known helper phages in these systems are temperate phages. Interestingly, the interference of the pirate phage to the helper phage occurs in a different manner between the SaPI-helper system and the P4-P2 system. SaPIs cannot lyse a helper lysogen upon infection, while when a helper phage lyse a SaPI lysogen, most of the phage particles produced are the SaPI particles. On the contrary, in the P4-P2 system, a pirate phage P4 can lyse a helper P2 lysogen to produce mostly the P4 particles, while when P2 phage lyses a P4 lysogen, most of the produced phages are the P2 particles. Here, the consequences of these different strategies in the pirate and helper phage spreading among uninfected host is analyzed by using mathematical models. It is found that SaPI's strategy interferes with the helper phage spreading significantly more than the P4's strategy, because SaPI interferes with the helper phage's main reproduction step, while P4 interferes only by forcing the helper lysogens to lyse. However, the interference is found to be weaker in the spatially structured environment than in the well-mixed environment. This is because, in the spatial setting, the system tends to self-organize so that the helper phages take over the front of propagation due to the need of helper phage for the pirate phage spreading.
Collapse
Affiliation(s)
- Namiko Mitarai
- The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, Copenhagen, 2100-DK, Denmark.
| |
Collapse
|
44
|
Benn G, Pyne ALB, Ryadnov MG, Hoogenboom BW. Imaging live bacteria at the nanoscale: comparison of immobilisation strategies. Analyst 2019; 144:6944-6952. [PMID: 31620716 PMCID: PMC7138128 DOI: 10.1039/c9an01185d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/10/2019] [Indexed: 12/17/2022]
Abstract
Atomic force microscopy (AFM) provides an effective, label-free technique enabling the imaging of live bacteria under physiological conditions with nanometre precision. However, AFM is a surface scanning technique, and the accuracy of its performance requires the effective and reliable immobilisation of bacterial cells onto substrates. Here, we compare the effectiveness of various chemical approaches to facilitate the immobilisation of Escherichia coli onto glass cover slips in terms of bacterial adsorption, viability and compatibility with correlative imaging by fluorescence microscopy. We assess surface functionalisation using gelatin, poly-l-lysine, Cell-Tak™, and Vectabond®. We describe how bacterial immobilisation, viability and suitability for AFM experiments depend on bacterial strain, buffer conditions and surface functionalisation. We demonstrate the use of such immobilisation by AFM images that resolve the porin lattice on the bacterial surface; local degradation of the bacterial cell envelope by an antimicrobial peptide (Cecropin B); and the formation of membrane attack complexes on the bacterial membrane.
Collapse
Affiliation(s)
- Georgina Benn
- London Centre for Nanotechnology
, University College London
,
London WC1H 0AH
, UK
.
- Institute of Structural and Molecular Biology
, University College London
,
London WC1E 6BT
, UK
- National Physical Laboratory
,
Hampton Road
, Teddington TW11 0LW
, UK
| | - Alice L. B. Pyne
- London Centre for Nanotechnology
, University College London
,
London WC1H 0AH
, UK
.
- Department of Materials Science and Engineering
, University of Sheffield
,
S1 3JD
, UK
| | - Maxim G. Ryadnov
- National Physical Laboratory
,
Hampton Road
, Teddington TW11 0LW
, UK
- Department of Physics
, King's College London
,
Strand Lane
, London WC2R 2LS
, UK
| | - Bart W. Hoogenboom
- London Centre for Nanotechnology
, University College London
,
London WC1H 0AH
, UK
.
- Institute of Structural and Molecular Biology
, University College London
,
London WC1E 6BT
, UK
- Department of Physics & Astronomy
, University College London
,
London WC1E 6BT
, UK
| |
Collapse
|
45
|
Ma AT, Tyrell B, Beld J. Specificity of cobamide remodeling, uptake and utilization in Vibrio cholerae. Mol Microbiol 2019; 113:89-102. [PMID: 31609521 DOI: 10.1111/mmi.14402] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2019] [Indexed: 12/11/2022]
Abstract
Cobamides are a group of compounds including vitamin B12 that can vary at the lower base position of the nucleotide loop. They are synthesized de novo by only a subset of prokaryotes, but some organisms encode partial biosynthesis pathways for converting one variant to another (remodeling) or completing biosynthesis from an intermediate (corrinoid salvaging). Here, we explore the cobamide specificity in Vibrio cholerae through examination of three natural variants representing major cobamide groups: commercially available cobalamin, and isolated pseudocobalamin and p-cresolylcobamide. We show that BtuB, the outer membrane corrinoid transporter, mediates the uptake of all three variants and the intermediate cobinamide. Our previous work suggested that V. cholerae could convert pseudocobalamin produced by cyanobacteria into cobalamin. In this work, cobamide specificity in V. cholerae is demonstrated by remodeling of pseudocobalamin and salvaging of cobinamide to produce cobalamin. Cobamide remodeling in V. cholerae is distinct from the canonical pathway requiring amidohydrolase CbiZ, and heterologous expression of V. cholerae CobS was sufficient for remodeling. Furthermore, function of V. cholerae cobamide-dependent methionine synthase MetH was robustly supported by cobalamin and p-cresolylcobamide, but not pseudocobalamin. Notably, the inability of V. cholerae to produce and utilize pseudocobalamin contrasts with enteric bacteria like Salmonella.
Collapse
Affiliation(s)
- Amy T Ma
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Breanna Tyrell
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Joris Beld
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| |
Collapse
|
46
|
Lozano Terol G, Gallego-Jara J, Sola Martínez RA, Cánovas Díaz M, de Diego Puente T. Engineering protein production by rationally choosing a carbon and nitrogen source using E. coli BL21 acetate metabolism knockout strains. Microb Cell Fact 2019; 18:151. [PMID: 31484572 PMCID: PMC6724240 DOI: 10.1186/s12934-019-1202-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/29/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Escherichia coli (E. coli) is a bacteria that is widely employed in many industries for the production of high interest bio-products such as recombinant proteins. Nevertheless, the use of E. coli for recombinant protein production may entail some disadvantages such as acetate overflow. Acetate is accumulated under some culture conditions, involves a decrease in biomass and recombinant protein production, and its metabolism is related to protein lysine acetylation. Thereby, the carbon and nitrogen sources employed are relevant factors in cell host metabolism, and the study of the central metabolism of E. coli and its regulation is essential for optimizing the production of biomass and recombinant proteins. In this study, our aim was to find the most favourable conditions for carrying out recombinant protein production in E. coli BL21 using two different approaches, namely, manipulation of the culture media composition and the deletion of genes involved in acetate metabolism and Nε-lysine acetylation. RESULTS We evaluated protein overexpression in E. coli BL21 wt and five mutant strains involved in acetate metabolism (Δacs, ΔackA and Δpta) and lysine acetylation (ΔpatZ and ΔcobB) grown in minimal medium M9 (inorganic ammonium nitrogen source) and in complex TB7 medium (peptide-based nitrogen source) supplemented with glucose (PTS carbon source) or glycerol (non-PTS carbon source). We observed a dependence of recombinant protein production on acetate metabolism and the carbon and nitrogen source employed. The use of complex medium supplemented with glycerol as a carbon source entails an increase in protein production and an efficient use of resources, since is a sub-product of biodiesel synthesis. Furthermore, the deletion of the ackA gene results in a fivefold increase in protein production with respect to the wt strain and a reduction in acetate accumulation. CONCLUSION The results showed that the use of diverse carbon and nitrogen sources and acetate metabolism knockout strains can redirect E. coli carbon fluxes to different pathways and affect the final yield of the recombinant protein bioprocess. Thereby, we obtained a fivefold increase in protein production and an efficient use of the resources employing the most suitable strain and culture conditions.
Collapse
Affiliation(s)
- Gema Lozano Terol
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain
| | - Julia Gallego-Jara
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain.
| | - Rosa Alba Sola Martínez
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain
| | - Manuel Cánovas Díaz
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain
| | - Teresa de Diego Puente
- Department of Biochemistry and Molecular Biology (B) and Immunology, Faculty of Chemistry, University of Murcia, Campus of Espinardo, Regional Campus of International Excellence ''Campus Mare Nostrum'', P.O. Box 4021, 30100, Murcia, Spain.
| |
Collapse
|
47
|
Complete Genome Sequence of Escherichia coli BE104, an MC4100 Derivative Lacking the Methionine Reductive Pathway. Microbiol Resour Announc 2019; 8:8/28/e00721-19. [PMID: 31296691 PMCID: PMC6624774 DOI: 10.1128/mra.00721-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this announcement, we present the complete annotated genome sequence of an Escherichia coli MC4100 mutant strain, BE104. This strain has several methionine sulfoxide reductase gene deletions, making it ideal for studying enzymes that alter the redox state of methionine. In this announcement, we present the complete annotated genome sequence of an Escherichia coli MC4100 mutant strain, BE104. This strain has several methionine sulfoxide reductase gene deletions, making it ideal for studying enzymes that alter the redox state of methionine.
Collapse
|
48
|
Rosano GL, Morales ES, Ceccarelli EA. New tools for recombinant protein production in Escherichia coli: A 5-year update. Protein Sci 2019; 28:1412-1422. [PMID: 31219641 DOI: 10.1002/pro.3668] [Citation(s) in RCA: 177] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Accepted: 06/10/2019] [Indexed: 12/11/2022]
Abstract
The production of proteins in sufficient amounts is key for their study or use as biotherapeutic agents. Escherichia coli is the host of choice for recombinant protein production given its fast growth, easy manipulation, and cost-effectiveness. As such, its protein production capabilities are continuously being improved. Also, the associated tools (such as plasmids and cultivation conditions) are subject of ongoing research to optimize product yield. In this work, we review the latest advances in recombinant protein production in E. coli.
Collapse
Affiliation(s)
- Germán L Rosano
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET. Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Enrique S Morales
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET. Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Eduardo A Ceccarelli
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET. Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| |
Collapse
|
49
|
Retapamulin-Assisted Ribosome Profiling Reveals the Alternative Bacterial Proteome. Mol Cell 2019; 74:481-493.e6. [PMID: 30904393 DOI: 10.1016/j.molcel.2019.02.017] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 01/25/2019] [Accepted: 02/12/2019] [Indexed: 12/21/2022]
Abstract
The use of alternative translation initiation sites enables production of more than one protein from a single gene, thereby expanding the cellular proteome. Although several such examples have been serendipitously found in bacteria, genome-wide mapping of alternative translation start sites has been unattainable. We found that the antibiotic retapamulin specifically arrests initiating ribosomes at start codons of the genes. Retapamulin-enhanced Ribo-seq analysis (Ribo-RET) not only allowed mapping of conventional initiation sites at the beginning of the genes, but strikingly, it also revealed putative internal start sites in a number of Escherichia coli genes. Experiments demonstrated that the internal start codons can be recognized by the ribosomes and direct translation initiation in vitro and in vivo. Proteins, whose synthesis is initiated at internal in-frame and out-of-frame start sites, can be functionally important and contribute to the "alternative" bacterial proteome. The internal start sites may also play regulatory roles in gene expression.
Collapse
|
50
|
Changes in Intrinsic Antibiotic Susceptibility during a Long-Term Evolution Experiment with Escherichia coli. mBio 2019; 10:mBio.00189-19. [PMID: 30837336 PMCID: PMC6401480 DOI: 10.1128/mbio.00189-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
High-level resistance often evolves when populations of bacteria are exposed to antibiotics, by either mutations or horizontally acquired genes. There is also variation in the intrinsic resistance levels of different bacterial strains and species that is not associated with any known history of exposure. In many cases, evolved resistance is costly to the bacteria, such that resistant types have lower fitness than their progenitors in the absence of antibiotics. Some longer-term studies have shown that bacteria often evolve compensatory changes that overcome these tradeoffs, but even those studies have typically lasted only a few hundred generations. In this study, we examine changes in the susceptibilities of 12 populations of Escherichia coli to 15 antibiotics after 2,000 and 50,000 generations without exposure to any antibiotic. On average, the evolved bacteria were more susceptible to most antibiotics than was their ancestor. The bacteria at 50,000 generations tended to be even more susceptible than after 2,000 generations, although most of the change occurred during the first 2,000 generations. Despite the general trend toward increased susceptibility, we saw diverse outcomes with different antibiotics. For streptomycin, which was the only drug to which the ancestral strain was highly resistant, none of the evolved lines showed any increased susceptibility. The independently evolved lineages often exhibited correlated responses to the antibiotics, with correlations usually corresponding to their modes of action. On balance, our study shows that bacteria with low levels of intrinsic resistance often evolve to become even more susceptible to antibiotics in the absence of corresponding selection.IMPORTANCE Resistance to antibiotics often evolves when bacteria encounter antibiotics. However, bacterial strains and species without any known exposure to these drugs also vary in their intrinsic susceptibility. In many cases, evolved resistance has been shown to be costly to the bacteria, such that resistant types have reduced competitiveness relative to their sensitive progenitors in the absence of antibiotics. In this study, we examined changes in the susceptibilities of 12 populations of Escherichia coli to 15 antibiotics after 2,000 and 50,000 generations without exposure to any drug. The evolved bacteria tended to become more susceptible to most antibiotics, with most of the change occurring during the first 2,000 generations, when the bacteria were undergoing rapid adaptation to their experimental conditions. On balance, our findings indicate that bacteria with low levels of intrinsic resistance can, in the absence of relevant selection, become even more susceptible to antibiotics.
Collapse
|