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Cronan JE. Biotin protein ligase as you like it: Either extraordinarily specific or promiscuous protein biotinylation. Proteins 2024; 92:435-448. [PMID: 37997490 PMCID: PMC10932917 DOI: 10.1002/prot.26642] [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: 10/27/2023] [Accepted: 11/09/2023] [Indexed: 11/25/2023]
Abstract
Biotin (vitamin H or B7) is a coenzyme essential for all forms of life. Biotin has biological activity only when covalently attached to a few key metabolic enzyme proteins. Most organisms have only one attachment enzyme, biotin protein ligase (BPL), which attaches biotin to all target proteins. The sequences of these proteins and their substrate proteins are strongly conserved throughout biology. Structures of both the biotin ligase- and biotin-acceptor domains of mammals, plants, several bacterial species, and archaea have been determined. These, together with mutational analyses of ligases and their protein substrates, illustrate the exceptional specificity of this protein modification. For example, the Escherichia coli BPL biotinylates only one of the >4000 cellular proteins. Several bifunctional bacterial biotin ligases transcriptionally regulate biotin synthesis and/or transport in concert with biotinylation. The human BPL has been demonstrated to play an important role in that mutations in the BPL encoding gene cause one form of the disease, biotin-responsive multiple carboxylase deficiency. Promiscuous mutant versions of several BPL enzymes release biotinoyl-AMP, the active intermediate of the ligase reaction, to solvent. The released biotinoyl-AMP acts as a chemical biotinylation reagent that modifies lysine residues of neighboring proteins in vivo. This proximity-dependent biotinylation (called BioID) approach has been heavily utilized in cell biology.
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Affiliation(s)
- John E Cronan
- Department of Microbiology, University of Illinois, Urbana, Illinois, USA
- Department of Biochemistry, University of Illinois, Urbana, Illinois, USA
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2
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Makrydaki E, Donini R, Krueger A, Royle K, Moya Ramirez I, Kuntz DA, Rose DR, Haslam SM, Polizzi KM, Kontoravdi C. Immobilized enzyme cascade for targeted glycosylation. Nat Chem Biol 2024:10.1038/s41589-023-01539-4. [PMID: 38321209 DOI: 10.1038/s41589-023-01539-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 12/21/2023] [Indexed: 02/08/2024]
Abstract
Glycosylation is a critical post-translational protein modification that affects folding, half-life and functionality. Glycosylation is a non-templated and heterogeneous process because of the promiscuity of the enzymes involved. We describe a platform for sequential glycosylation reactions for tailored sugar structures (SUGAR-TARGET) that allows bespoke, controlled N-linked glycosylation in vitro enabled by immobilized enzymes produced with a one-step immobilization/purification method. We reconstruct a reaction cascade mimicking a glycosylation pathway where promiscuity naturally exists to humanize a range of proteins derived from different cellular systems, yielding near-homogeneous glycoforms. Immobilized β-1,4-galactosyltransferase is used to enhance the galactosylation profile of three IgGs, yielding 80.2-96.3% terminal galactosylation. Enzyme recycling is demonstrated for a reaction time greater than 80 h. The platform is easy to implement, modular and reusable and can therefore produce homogeneous glycan structures derived from various hosts for functional and clinical evaluation.
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Affiliation(s)
- Elli Makrydaki
- Department of Chemical Engineering, Imperial College London, London, UK
| | - Roberto Donini
- Department of Life Sciences, Imperial College London, London, UK
| | - Anja Krueger
- Department of Life Sciences, Imperial College London, London, UK
| | - Kate Royle
- Department of Chemical Engineering, Imperial College London, London, UK
| | - Ignacio Moya Ramirez
- Department of Chemical Engineering, Imperial College London, London, UK
- Departamento de Ingeniería Química, Universidad de Granada, Granada, Spain
| | - Douglas A Kuntz
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
| | - David R Rose
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| | - Stuart M Haslam
- Department of Life Sciences, Imperial College London, London, UK
| | - Karen M Polizzi
- Department of Chemical Engineering, Imperial College London, London, UK.
| | - Cleo Kontoravdi
- Department of Chemical Engineering, Imperial College London, London, UK.
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3
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Galisteo C, de la Haba RR, Sánchez-Porro C, Ventosa A. Biotin pathway in novel Fodinibius salsisoli sp. nov., isolated from hypersaline soils and reclassification of the genus Aliifodinibius as Fodinibius. Front Microbiol 2023; 13:1101464. [PMID: 36777031 PMCID: PMC9909488 DOI: 10.3389/fmicb.2022.1101464] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/22/2022] [Indexed: 01/27/2023] Open
Abstract
Hypersaline soils are extreme environments that have received little attention until the last few years. Their halophilic prokaryotic population seems to be more diverse than those of well-known aquatic systems. Among those inhabitants, representatives of the family Balneolaceae (phylum Balneolota) have been described to be abundant, but very few members have been isolated and characterized to date. This family comprises the genera Aliifodinibius and Fodinibius along with four others. A novel strain, designated 1BSP15-2V2T, has been isolated from hypersaline soils located in the Odiel Saltmarshes Natural Area (Southwest Spain), which appears to represent a new species related to the genus Aliifodinibius. However, comparative genomic analyses of members of the family Balneolaceae have revealed that the genera Aliifodinibius and Fodinibius belong to a single genus, hence we propose the reclassification of the species of the genus Aliifodinibius into the genus Fodinibius, which was first described. The novel strain is thus described as Fodinibius salsisoli sp. nov., with 1BSP15-2V2T (=CCM 9117T = CECT 30246T) as the designated type strain. This species and other closely related ones show abundant genomic recruitment within 80-90% identity range when searched against several hypersaline soil metagenomic databases investigated. This might suggest that there are still uncultured, yet abundant closely related representatives to this family present in these environments. In-depth in-silico analysis of the metabolism of Fodinibius showed that the biotin biosynthesis pathway was present in the genomes of strain 1BSP15-2V2T and other species of the family Balneolaceae, which could entail major implications in their community role providing this vitamin to other organisms that depend on an exogenous source of this nutrient.
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4
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Salinas A, McGregor C, Irorere V, Arenas-López C, Bommareddy RR, Winzer K, Minton NP, Kovács K. Metabolic engineering of Cupriavidus necator H16 for heterotrophic and autotrophic production of 3-hydroxypropionic acid. Metab Eng 2022; 74:178-190. [DOI: 10.1016/j.ymben.2022.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/29/2022] [Accepted: 10/30/2022] [Indexed: 11/06/2022]
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5
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The Classical, Yet Controversial, First Enzyme of Lipid Synthesis: Escherichia coli Acetyl-CoA Carboxylase. Microbiol Mol Biol Rev 2021; 85:e0003221. [PMID: 34132100 DOI: 10.1128/mmbr.00032-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Escherichia coli acetyl-CoA carboxylase (ACC), the enzyme responsible for synthesis of malonyl-CoA, the building block of fatty acid synthesis, is the paradigm bacterial ACC. Many reports on the structures and stoichiometry of the four subunits comprising the active enzyme as well as on regulation of ACC activity and expression have appeared in the almost 20 years since this subject was last reviewed. This review seeks to update and expand on these reports.
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Kozaeva E, Volkova S, Matos MRA, Mezzina MP, Wulff T, Volke DC, Nielsen LK, Nikel PI. Model-guided dynamic control of essential metabolic nodes boosts acetyl-coenzyme A-dependent bioproduction in rewired Pseudomonas putida. Metab Eng 2021; 67:373-386. [PMID: 34343699 DOI: 10.1016/j.ymben.2021.07.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/23/2021] [Accepted: 07/29/2021] [Indexed: 01/16/2023]
Abstract
Pseudomonas putida is evolutionarily endowed with features relevant for bioproduction, especially under harsh operating conditions. The rich metabolic versatility of this species, however, comes at the price of limited formation of acetyl-coenzyme A (CoA) from sugar substrates. Since acetyl-CoA is a key metabolic precursor for a number of added-value products, in this work we deployed an in silico-guided rewiring program of central carbon metabolism for upgrading P. putida as a host for acetyl-CoA-dependent bioproduction. An updated kinetic model, integrating fluxomics and metabolomics datasets in addition to manually-curated information of enzyme mechanisms, identified targets that would lead to increased acetyl-CoA levels. Based on these predictions, a set of plasmids based on clustered regularly interspaced short palindromic repeats (CRISPR) and dead CRISPR-associated protein 9 (dCas9) was constructed to silence genes by CRISPR interference (CRISPRi). Dynamic reduction of gene expression of two key targets (gltA, encoding citrate synthase, and the essential accA gene, encoding subunit A of the acetyl-CoA carboxylase complex) mediated an 8-fold increase in the acetyl-CoA content of rewired P. putida. Poly(3-hydroxybutyrate) (PHB) was adopted as a proxy of acetyl-CoA availability, and two synthetic pathways were engineered for biopolymer accumulation. By including cell morphology as an extra target for the CRISPRi approach, fully rewired P. putida strains programmed for PHB accumulation had a 5-fold increase in PHB titers in bioreactor cultures using glucose. Thus, the strategy described herein allowed for rationally redirecting metabolic fluxes in P. putida from central metabolism towards product biosynthesis-especially relevant when deletion of essential pathways is not an option.
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Affiliation(s)
- Ekaterina Kozaeva
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Svetlana Volkova
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Marta R A Matos
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Mariela P Mezzina
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Tune Wulff
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Daniel C Volke
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Lars K Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens Lyngby, Denmark; Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Pablo I Nikel
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
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Sirithanakorn C, Cronan JE. Biotin, a universal and essential cofactor: Synthesis, ligation and regulation. FEMS Microbiol Rev 2021; 45:6081095. [PMID: 33428728 DOI: 10.1093/femsre/fuab003] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/08/2021] [Indexed: 12/22/2022] Open
Abstract
Biotin is a covalently attached enzyme cofactor required for intermediary metabolism in all three domains of life. Several important human pathogens (e.g. Mycobacterium tuberculosis) require biotin synthesis for pathogenesis. Humans lack a biotin synthetic pathway hence bacterial biotin synthesis is a prime target for new therapeutic agents. The biotin synthetic pathway is readily divided into early and late segments. Although pimelate, a seven carbon α,ω-dicarboxylic acid that contributes seven of the ten biotin carbons atoms, was long known to be a biotin precursor, its biosynthetic pathway was a mystery until the E. coli pathway was discovered in 2010. Since then, diverse bacteria encode evolutionarily distinct enzymes that replace enzymes in the E. coli pathway. Two new bacterial pimelate synthesis pathways have been elucidated. In contrast to the early pathway the late pathway, assembly of the fused rings of the cofactor, was long thought settled. However, a new enzyme that bypasses a canonical enzyme was recently discovered as well as homologs of another canonical enzyme that functions in synthesis of another protein-bound coenzyme, lipoic acid. Most bacteria tightly regulate transcription of the biotin synthetic genes in a biotin-responsive manner. The bifunctional biotin ligases which catalyze attachment of biotin to its cognate enzymes and repress biotin gene transcription are best understood regulatory system.
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Affiliation(s)
- Chaiyos Sirithanakorn
- Faculty of Medicine, King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand.,Department of Microbiology, University of Illinois, Urbana, IL 61801, USA
| | - John E Cronan
- Department of Microbiology, University of Illinois, Urbana, IL 61801, USA.,Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
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8
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Lama S, Kim Y, Nguyen DT, Im CH, Sankaranarayanan M, Park S. Production of 3-hydroxypropionic acid from acetate using metabolically-engineered and glucose-grown Escherichia coli. BIORESOURCE TECHNOLOGY 2021; 320:124362. [PMID: 33186840 DOI: 10.1016/j.biortech.2020.124362] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 06/11/2023]
Abstract
Acetate can be used as carbon feedstock for the production of 3-hydroxypropionic acid (3-HP), but the production level was low due to inefficient cell growth on acetate. To better utilize acetate, a two-stage strategy, whereby glucose is used for cell growth and acetate for 3-HP formation, was attempted. Dissected malonyl-CoA reductase of Chloroflexus aurantiacus, alone or along with acetyl-CoA carboxylase and/or transhydrogenase, was overexpressed, and by-products formation pathway, glyoxylate shunt (GS) and gluconeogenesis were modified. When GS or gluconeogenesis was disrupted, cell growth on glucose was not hampered, while on acetate it was completely abolished. Consequently, 3-HP production, at production stage, were low, though 3-HP yield on acetate was increased, especially in the case of aceA deletion. In two-stage bioreactor, strain with upregulated GS produced 7.3 g/L 3-HP with yield of 0.26 mol/mol acetate. This study suggests that two-stage cultivation is a good strategy for 3-HP production from acetate.
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Affiliation(s)
- Suman Lama
- School of Energy and Chemical Engineering, UNIST, 50, Ulsan 44919, Republic of Korea
| | - Yeonhee Kim
- School of Energy and Chemical Engineering, UNIST, 50, Ulsan 44919, Republic of Korea
| | - Dat Tuan Nguyen
- School of Energy and Chemical Engineering, UNIST, 50, Ulsan 44919, Republic of Korea
| | - Chae Ho Im
- School of Energy and Chemical Engineering, UNIST, 50, Ulsan 44919, Republic of Korea; Department of Biology and Bioengineering, Division of Industrial Biotechnology, Chalmers University of Technology, kemivagen 10, 412 96 Goteborg, Sweden
| | - Mugesh Sankaranarayanan
- Department of Biotechnology, Vel Tech Rangarajan Dr. Sagunthala R&D Institute of Science and Technology, Avadi, Chennai 600062, India
| | - Sunghoon Park
- School of Energy and Chemical Engineering, UNIST, 50, Ulsan 44919, Republic of Korea.
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9
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Eggers J, Strittmatter CS, Küsters K, Biller E, Steinbüchel A. Biotin Synthesis in Ralstonia eutropha H16 Utilizes Pimeloyl Coenzyme A and Can Be Regulated by the Amount of Acceptor Protein. Appl Environ Microbiol 2020; 86:e01512-20. [PMID: 32680858 PMCID: PMC7480372 DOI: 10.1128/aem.01512-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 07/13/2020] [Indexed: 11/20/2022] Open
Abstract
The biotin metabolism of the Gram-negative facultative chemolithoautotrophic bacterium Ralstonia eutropha (syn. Cupriavidus necator), which is used for biopolymer production in industry, was investigated. A biotin auxotroph mutant lacking bioF was generated, and biotin depletion in the cells and the minimal biotin demand of a biotin-auxotrophic R. eutropha strain were determined. Three consecutive cultivations in biotin-free medium were necessary to prevent growth of the auxotrophic mutant, and 40 ng/ml biotin was sufficient to promote cell growth. Nevertheless, 200 ng/ml biotin was necessary to ensure growth comparable to that of the wild type, which is similar to the demand of biotin-auxotrophic mutants among other prokaryotic and eukaryotic microbes. A phenotypic complementation of the R. eutropha ΔbioF mutant was only achieved by homologous expression of bioF of R. eutropha or heterologous expression of bioF of Bacillus subtilis but not by bioF of Escherichia coli Together with the results from bioinformatic analysis of BioFs, this leads to the assumption that the intermediate of biotin synthesis in R. eutropha is pimeloyl-CoA instead of pimeloyl-acyl carrier protein (ACP) like in the Gram-positive B. subtilis Internal biotin content was enhanced by homologous expression of accB, whereas homologous expression of accB and accC2 in combination led to decreased biotin concentrations in the cells. Although a DNA-binding domain of the regulator protein BirA is missing, biotin synthesis seemed to be influenced by the amount of acceptor protein present.IMPORTANCERalstonia eutropha is applied in industry for the production of biopolymers and serves as a research platform for the production of diverse fine chemicals. Due to its ability to grow on hydrogen and carbon dioxide as the sole carbon and energy source, R. eutropha is often utilized for metabolic engineering to convert inexpensive resources into value-added products. The understanding of the metabolic pathways in this bacterium is mandatory for further bioengineering of the strain and for the development of new strategies for biotechnological production.
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Affiliation(s)
- Jessica Eggers
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Carl Simon Strittmatter
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Kira Küsters
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Emre Biller
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster, Germany
- Environmental Sciences Department, King Abdulaziz University, Jeddah, Saudi Arabia
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10
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Schober AF, Mathis AD, Ingle C, Park JO, Chen L, Rabinowitz JD, Junier I, Rivoire O, Reynolds KA. A Two-Enzyme Adaptive Unit within Bacterial Folate Metabolism. Cell Rep 2020; 27:3359-3370.e7. [PMID: 31189117 DOI: 10.1016/j.celrep.2019.05.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 04/05/2019] [Accepted: 05/09/2019] [Indexed: 11/29/2022] Open
Abstract
Enzyme function and evolution are influenced by the larger context of a metabolic pathway. Deleterious mutations or perturbations in one enzyme can often be compensated by mutations to others. We used comparative genomics and experiments to examine evolutionary interactions with the essential metabolic enzyme dihydrofolate reductase (DHFR). Analyses of synteny and co-occurrence across bacterial species indicate that DHFR is coupled to thymidylate synthase (TYMS) but relatively independent from the rest of folate metabolism. Using quantitative growth rate measurements and forward evolution in Escherichia coli, we demonstrate that the two enzymes adapt as a relatively independent unit in response to antibiotic stress. Metabolomic profiling revealed that TYMS activity must not exceed DHFR activity to prevent the depletion of reduced folates and the accumulation of the intermediate dihydrofolate. Comparative genomics analyses identified >200 gene pairs with similar statistical signatures of modular co-evolution, suggesting that cellular pathways may be decomposable into small adaptive units.
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Affiliation(s)
- Andrew F Schober
- The Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Andrew D Mathis
- The Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Christine Ingle
- The Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Junyoung O Park
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544, USA
| | - Li Chen
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Joshua D Rabinowitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Ivan Junier
- Centre National de la Recherche Scientifique, Université Grenoble Alpes, TIMC-IMAG, F-38000 Grenoble, France
| | - Olivier Rivoire
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, F-75005 Paris, France
| | - Kimberly A Reynolds
- The Green Center for Systems Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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11
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Wei W, Zhang Y, Gao R, Li J, Xu Y, Wang S, Ji Q, Feng Y. Crystal structure and acetylation of BioQ suggests a novel regulatory switch for biotin biosynthesis in Mycobacterium smegmatis. Mol Microbiol 2018; 109:642-662. [PMID: 29995988 DOI: 10.1111/mmi.14066] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2018] [Indexed: 12/24/2022]
Abstract
Biotin (vitamin B7), a sulfur-containing fatty acid derivative, is a nutritional virulence factor in certain mycobacterial species. Tight regulation of biotin biosynthesis is important because production of biotin is an energetically expensive process requiring 15-20 equivalents of ATP. The Escherichia coli bifunctional BirA is a prototypical biotin regulatory system. In contrast, mycobacterial BirA is an unusual biotin protein ligase without DNA-binding domain. Recently, we established a novel two-protein paradigm of BioQ-BirA. However, structural and molecular mechanism for BioQ is poorly understood. Here, we report crystal structure of the M. smegmatis BioQ at 1.9 Å resolution. Structure-guided functional mapping defined a seven residues-requiring motif for DNA-binding activity. Western blot and MALDI-TOF MS allowed us to unexpectedly discover that the K47 acetylation activates crosstalking of BioQ to its cognate DNA. More intriguingly, excess of biotin augments the acetylation status of BioQ in M. smegmatis. It seems likely that BioQ acetylation proceeds via a non-enzymatic mechanism. Mutation of this acetylation site K47 in BioQ significantly impairs its regulatory role in vivo. This explains in part (if not all) why BioQ has no detectable requirement of the presumable bio-5'-AMP effecter, which is a well-known ligand for the paradigm E. coli BirA regulator system. Unlike the scenario seen with E. coli carrying a single biotinylated protein, AccB, genome-wide search and Streptavidin blot revealed that no less than seven proteins require the rare post-translational modification, biotinylation in M. smegmatis, validating its physiological demand for biotin at relatively high level. Taken together, our finding defines a novel biotin regulatory machinery by BioQ, posing a possibility that development of new antibiotics targets biotin, the limited nutritional virulence factor in certain pathogenic mycobacterial species.
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Affiliation(s)
- Wenhui Wei
- Department of Medical Microbiology & Parasitology and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China.,College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Yifei Zhang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Rongsui Gao
- Department of Medical Microbiology & Parasitology and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
| | - Jun Li
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang, 310014, China
| | - Yongchang Xu
- Department of Medical Microbiology & Parasitology and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China
| | - Shihua Wang
- College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Quanjiang Ji
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Youjun Feng
- Department of Medical Microbiology & Parasitology and Department of General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310058, China.,Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, School of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
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12
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Baron F, Bonnassie S, Alabdeh M, Cochet MF, Nau F, Guérin-Dubiard C, Gautier M, Andrews SC, Jan S. Global Gene-expression Analysis of the Response of Salmonella Enteritidis to Egg White Exposure Reveals Multiple Egg White-imposed Stress Responses. Front Microbiol 2017; 8:829. [PMID: 28553268 PMCID: PMC5428311 DOI: 10.3389/fmicb.2017.00829] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 04/24/2017] [Indexed: 12/20/2022] Open
Abstract
Chicken egg white protects the embryo from bacterial invaders by presenting an assortment of antagonistic activities that combine together to both kill and inhibit growth. The key features of the egg white anti-bacterial system are iron restriction, high pH, antibacterial peptides and proteins, and viscosity. Salmonella enterica serovar Enteritidis is the major pathogen responsible for egg-borne infection in humans, which is partly explained by its exceptional capacity for survival under the harsh conditions encountered within egg white. However, at temperatures up to 42°C, egg white exerts a much stronger bactericidal effect on S. Enteritidis than at lower temperatures, although the mechanism of egg white-induced killing is only partly understood. Here, for the first time, the impact of exposure of S. Enteritidis to egg white under bactericidal conditions (45°C) is explored by global-expression analysis. A large-scale (18.7% of genome) shift in transcription is revealed suggesting major changes in specific aspects of S. Enteritidis physiology: induction of egg white related stress-responses (envelope damage, exposure to heat and alkalinity, and translation shutdown); shift in energy metabolism from respiration to fermentation; and enhanced micronutrient provision (due to iron and biotin restriction). Little evidence of DNA damage or redox stress was obtained. Instead, data are consistent with envelope damage resulting in cell death by lysis. A surprise was the high degree of induction of hexonate/hexuronate utilization genes, despite no evidence indicating the presence of these substrates in egg white.
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Affiliation(s)
- Florence Baron
- Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
- INRA, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
| | - Sylvie Bonnassie
- Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
- INRA, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
- Science de la Vie et de la Terre, Université de Rennes IRennes, France
| | - Mariah Alabdeh
- Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
- INRA, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
| | - Marie-Françoise Cochet
- Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
- INRA, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
| | - Françoise Nau
- Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
- INRA, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
| | - Catherine Guérin-Dubiard
- Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
- INRA, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
| | - Michel Gautier
- Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
- INRA, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
| | | | - Sophie Jan
- Agrocampus Ouest, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
- INRA, UMR1253 Science et Technologie du Lait et de l'OeufRennes, France
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13
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Henke SK, Cronan JE. The Staphylococcus aureus group II biotin protein ligase BirA is an effective regulator of biotin operon transcription and requires the DNA binding domain for full enzymatic activity. Mol Microbiol 2016; 102:417-429. [PMID: 27445042 PMCID: PMC5116234 DOI: 10.1111/mmi.13470] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2016] [Indexed: 11/30/2022]
Abstract
Group II biotin protein ligases (BPLs) are characterized by the presence of an N-terminal DNA binding domain that functions in transcriptional regulation of the genes of biotin biosynthesis and transport. The Staphylococcus aureus Group II BPL which is called BirA has been reported to bind an imperfect inverted repeat located upstream of the biotin synthesis operon. DNA binding by other Group II BPLs requires dimerization of the protein which is triggered by synthesis of biotinoyl-AMP (biotinoyl-adenylate), the intermediate in the ligation of biotin to its cognate target proteins. However, the S. aureus BirA was reported to dimerize and bind DNA in the absence of biotin or biotinoyl-AMP (Soares da Costa et al. (2014) Mol Microbiol 91: 110-120). These in vitro results argued that the protein would be unable to respond to the levels of biotin or acceptor proteins and thus would lack the regulatory properties of the other characterized BirA proteins. We tested the regulatory function of the protein using an in vivo model system and examined its DNA binding properties in vitro using electrophoretic mobility shift and fluorescence anisotropy analyses. We report that the S. aureus BirA is an effective regulator of biotin operon transcription and that the prior data can be attributed to artifacts of mobility shift analyses. We also report that deletion of the DNA binding domain of the S. aureus BirA results in loss of virtually all of its ligation activity.
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Affiliation(s)
- Sarah K Henke
- Departments of Microbiology, University of Illinois, Urbana, Illinois, 61801, USA
| | - John E Cronan
- Departments of Microbiology, University of Illinois, Urbana, Illinois, 61801, USA.
- Biochemistry, University of Illinois, Urbana, Illinois, 61801, USA.
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14
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Abstract
Two vitamins, biotin and lipoic acid, are essential in all three domains of life. Both coenzymes function only when covalently attached to key metabolic enzymes. There they act as "swinging arms" that shuttle intermediates between two active sites (= covalent substrate channeling) of key metabolic enzymes. Although biotin was discovered over 100 years ago and lipoic acid 60 years ago, it was not known how either coenzyme is made until recently. In Escherichia coli the synthetic pathways for both coenzymes have now been worked out for the first time. The late steps of biotin synthesis, those involved in assembling the fused rings, were well described biochemically years ago, although recent progress has been made on the BioB reaction, the last step of the pathway in which the biotin sulfur moiety is inserted. In contrast, the early steps of biotin synthesis, assembly of the fatty acid-like "arm" of biotin were unknown. It has now been demonstrated that the arm is made by using disguised substrates to gain entry into the fatty acid synthesis pathway followed by removal of the disguise when the proper chain length is attained. The BioC methyltransferase is responsible for introducing the disguise, and the BioH esterase is responsible for its removal. In contrast to biotin, which is attached to its cognate proteins as a finished molecule, lipoic acid is assembled on its cognate proteins. An octanoyl moiety is transferred from the octanoyl acyl carrier protein of fatty acid synthesis to a specific lysine residue of a cognate protein by the LipB octanoyltransferase followed by sulfur insertion at carbons C-6 and C-8 by the LipA lipoyl synthetase. Assembly on the cognate proteins regulates the amount of lipoic acid synthesized, and, thus, there is no transcriptional control of the synthetic genes. In contrast, transcriptional control of the biotin synthetic genes is wielded by a remarkably sophisticated, yet simple, system, exerted through BirA, a dual-function protein that both represses biotin operon transcription and ligates biotin to its cognate proteins.
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15
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Abstract
The pathways in Escherichia coli and (largely by analogy) S. enterica remain the paradigm of bacterial lipid synthetic pathways, although recently considerable diversity among bacteria in the specific areas of lipid synthesis has been demonstrated. The structural biology of the fatty acid synthetic proteins is essentially complete. However, the membrane-bound enzymes of phospholipid synthesis remain recalcitrant to structural analyses. Recent advances in genetic technology have allowed the essentialgenes of lipid synthesis to be tested with rigor, and as expected most genes are essential under standard growth conditions. Conditionally lethal mutants are available in numerous genes, which facilitates physiological analyses. The array of genetic constructs facilitates analysis of the functions of genes from other organisms. Advances in mass spectroscopy have allowed very accurate and detailed analyses of lipid compositions as well as detection of the interactions of lipid biosynthetic proteins with one another and with proteins outside the lipid pathway. The combination of these advances has resulted in use of E. coli and S. enterica for discovery of new antimicrobials targeted to lipid synthesis and in deciphering the molecular actions of known antimicrobials. Finally,roles for bacterial fatty acids other than as membrane lipid structural components have been uncovered. For example, fatty acid synthesis plays major roles in the synthesis of the essential enzyme cofactors, biotin and lipoic acid. Although other roles for bacterial fatty acids, such as synthesis of acyl-homoserine quorum-sensing molecules, are not native to E. coli introduction of the relevant gene(s) synthesis of these foreign molecules readily proceeds and the sophisticated tools available can used to decipher the mechanisms of synthesis of these molecules.
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16
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Abstract
Two vitamins, biotin and lipoic acid, are essential in all three domains of life. Both coenzymes function only when covalently attached to key metabolic enzymes. There they act as "swinging arms" that shuttle intermediates between two active sites (= covalent substrate channeling) of key metabolic enzymes. Although biotin was discovered over 100 years ago and lipoic acid was discovered 60 years ago, it was not known how either coenzyme is made until recently. In Escherichia coli the synthetic pathways for both coenzymes have now been worked out for the first time. The late steps of biotin synthesis, those involved in assembling the fused rings, were well described biochemically years ago, although recent progress has been made on the BioB reaction, the last step of the pathway, in which the biotin sulfur moiety is inserted. In contrast, the early steps of biotin synthesis, assembly of the fatty acid-like "arm" of biotin, were unknown. It has now been demonstrated that the arm is made by using disguised substrates to gain entry into the fatty acid synthesis pathway followed by removal of the disguise when the proper chain length is attained. The BioC methyltransferase is responsible for introducing the disguise and the BioH esterase for its removal. In contrast to biotin, which is attached to its cognate proteins as a finished molecule, lipoic acid is assembled on its cognate proteins. An octanoyl moiety is transferred from the octanoyl-ACP of fatty acid synthesis to a specific lysine residue of a cognate protein by the LipB octanoyl transferase, followed by sulfur insertion at carbons C6 and C8 by the LipA lipoyl synthetase. Assembly on the cognate proteins regulates the amount of lipoic acid synthesized, and thus there is no transcriptional control of the synthetic genes. In contrast, transcriptional control of the biotin synthetic genes is wielded by a remarkably sophisticated, yet simple, system exerted through BirA, a dual-function protein that both represses biotin operon transcription and ligates biotin to its cognate protein.
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17
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Henke SK, Cronan JE. Successful conversion of the Bacillus subtilis BirA Group II biotin protein ligase into a Group I ligase. PLoS One 2014; 9:e96757. [PMID: 24816803 PMCID: PMC4016012 DOI: 10.1371/journal.pone.0096757] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 04/07/2014] [Indexed: 11/19/2022] Open
Abstract
Group II biotin protein ligases (BPLs) are characterized by the presence of an N-terminal DNA binding domain that allows transcriptional regulation of biotin biosynthetic and transport genes whereas Group I BPLs lack this N-terminal domain. The Bacillus subtilis BPL, BirA, is classified as a Group II BPL based on sequence predictions of an N-terminal helix-turn-helix motif and mutational alteration of its regulatory properties. We report evidence that B. subtilis BirA is a Group II BPL that regulates transcription at three genomic sites: bioWAFDBI, yuiG and yhfUTS. Moreover, unlike the paradigm Group II BPL, E. coli BirA, the N-terminal DNA binding domain can be deleted from Bacillus subtilis BirA without adverse effects on its ligase function. This is the first example of successful conversion of a Group II BPL to a Group I BPL with retention of full ligase activity.
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Affiliation(s)
- Sarah K. Henke
- Department of Microbiology, University of Illinois, Urbana, Illinois, United States of America
| | - John E. Cronan
- Department of Microbiology, University of Illinois, Urbana, Illinois, United States of America
- Department of Biochemistry, University of Illinois, Urbana, Illinois, United States of America
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18
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Janßen HJ, Steinbüchel A. Fatty acid synthesis in Escherichia coli and its applications towards the production of fatty acid based biofuels. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:7. [PMID: 24405789 PMCID: PMC3896788 DOI: 10.1186/1754-6834-7-7] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 12/24/2013] [Indexed: 05/04/2023]
Abstract
The idea of renewable and regenerative resources has inspired research for more than a hundred years. Ideally, the only spent energy will replenish itself, like plant material, sunlight, thermal energy or wind. Biodiesel or ethanol are examples, since their production relies mainly on plant material. However, it has become apparent that crop derived biofuels will not be sufficient to satisfy future energy demands. Thus, especially in the last decade a lot of research has focused on the production of next generation biofuels. A major subject of these investigations has been the microbial fatty acid biosynthesis with the aim to produce fatty acids or derivatives for substitution of diesel. As an industrially important organism and with the best studied microbial fatty acid biosynthesis, Escherichia coli has been chosen as producer in many of these studies and several reviews have been published in the fields of E. coli fatty acid biosynthesis or biofuels. However, most reviews discuss only one of these topics in detail, despite the fact, that a profound understanding of the involved enzymes and their regulation is necessary for efficient genetic engineering of the entire pathway. The first part of this review aims at summarizing the knowledge about fatty acid biosynthesis of E. coli and its regulation, and it provides the connection towards the production of fatty acids and related biofuels. The second part gives an overview about the achievements by genetic engineering of the fatty acid biosynthesis towards the production of next generation biofuels. Finally, the actual importance and potential of fatty acid-based biofuels will be discussed.
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Affiliation(s)
- Helge Jans Janßen
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 3, D-48149, Münster, Germany
| | - Alexander Steinbüchel
- Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 3, D-48149, Münster, Germany
- Environmental Sciences Department, King Abdulaziz University, Jeddah, Saudi Arabia
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19
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Brucella BioR regulator defines a complex regulatory mechanism for bacterial biotin metabolism. J Bacteriol 2013; 195:3451-67. [PMID: 23729648 DOI: 10.1128/jb.00378-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The enzyme cofactor biotin (vitamin H or B7) is an energetically expensive molecule whose de novo biosynthesis requires 20 ATP equivalents. It seems quite likely that diverse mechanisms have evolved to tightly regulate its biosynthesis. Unlike the model regulator BirA, a bifunctional biotin protein ligase with the capability of repressing the biotin biosynthetic pathway, BioR has been recently reported by us as an alternative machinery and a new type of GntR family transcriptional factor that can repress the expression of the bioBFDAZ operon in the plant pathogen Agrobacterium tumefaciens. However, quite unusually, a closely related human pathogen, Brucella melitensis, has four putative BioR-binding sites (both bioR and bioY possess one site in the promoter region, whereas the bioBFDAZ [bio] operon contains two tandem BioR boxes). This raised the question of whether BioR mediates the complex regulatory network of biotin metabolism. Here, we report that this is the case. The B. melitensis BioR ortholog was overexpressed and purified to homogeneity, and its solution structure was found to be dimeric. Functional complementation in a bioR isogenic mutant of A. tumefaciens elucidated that Brucella BioR is a functional repressor. Electrophoretic mobility shift assays demonstrated that the four predicted BioR sites of Brucella plus the BioR site of A. tumefaciens can all interact with the Brucella BioR protein. In a reporter strain that we developed on the basis of a double mutant of A. tumefaciens (the ΔbioR ΔbioBFDA mutant), the β-galactosidase (β-Gal) activity of three plasmid-borne transcriptional fusions (bioBbme-lacZ, bioYbme-lacZ, and bioRbme-lacZ) was dramatically decreased upon overexpression of Brucella bioR. Real-time quantitative PCR analyses showed that the expression of bioBFDA and bioY is significantly elevated upon removal of bioR from B. melitensis. Together, we conclude that Brucella BioR is not only a negative autoregulator but also a repressor of expression of bioY and bio operons that separately function in biotin transport and the biosynthesis pathway.
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20
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Altered regulation of Escherichia coli biotin biosynthesis in BirA superrepressor mutant strains. J Bacteriol 2011; 194:1113-26. [PMID: 22210766 DOI: 10.1128/jb.06549-11] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transcription of the Escherichia coli biotin (bio) operon is directly regulated by the biotin protein ligase BirA, the enzyme that covalently attaches biotin to its cognate acceptor proteins. Binding of BirA to the bio operator requires dimerization of the protein, which is triggered by BirA-catalyzed synthesis of biotinoyl-adenylate (biotinoyl-5'-AMP), the obligatory intermediate of the ligation reaction. Although several aspects of this regulatory system are well understood, no BirA superrepressor mutant strains had been isolated. Such superrepressor BirA proteins would repress the biotin operon transcription in vivo at biotin concentrations well below those needed for repression by wild-type BirA. We isolated mutant strains having this phenotype by a combined selection-screening approach and resolved multiple mutations to give several birA superrepressor alleles, each having a single mutation, all of which showed repression dominant over that of the wild-type allele. All of these mutant strains repressed bio operon transcription in vivo at biotin concentrations that gave derepression of the wild-type strain and retained sufficient ligation activity for growth when overexpressed. All of the strains except that encoding G154D BirA showed derepression of bio operon transcription upon overproduction of a biotin-accepting protein. In BirA, G154D was a lethal mutation in single copy, and the purified protein was unable to transfer biotin from enzyme-bound biotinoyl-adenylate either to the natural acceptor protein or to a biotin-accepting peptide sequence. Consistent with the transcriptional repression data, each of the purified mutant proteins showed increased affinity for the biotin operator DNA in electrophoretic mobility shift assays. Surprisingly, although most of the mutations were located in the catalytic domain, all of those tested, except G154D BirA, had normal ligase activity. Most of the mutations that gave superrepressor phenotypes altered residues located close to the dimerization interface of BirA. However, two mutations were located at sites well removed from the interface. The properties of the superrepressor mutants strengthen and extend other data indicating that BirA function entails extensive interactions among the three domains of the protein and show that normal ligase activity does not ensure normal DNA binding.
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21
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Polyak SW, Abell AD, Wilce MCJ, Zhang L, Booker GW. Structure, function and selective inhibition of bacterial acetyl-coa carboxylase. Appl Microbiol Biotechnol 2011; 93:983-92. [PMID: 22183085 DOI: 10.1007/s00253-011-3796-z] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 11/21/2011] [Accepted: 11/24/2011] [Indexed: 11/24/2022]
Abstract
Acetyl-CoA carboxylase (ACC) catalyses the first committed step in fatty acid biosynthesis: a metabolic pathway required for several important biological processes including the synthesis and maintenance of cellular membranes. ACC employs a covalently attached biotin moiety to bind a carboxyl anion and then transfer it to acetyl-CoA, yielding malonyl-CoA. These activities occur at two different subsites: the biotin carboxylase (BC) and carboxyltransferase (CT). Structural biology, together with small molecule inhibitor studies, has provided new insights into the molecular mechanisms that govern ACC catalysis, specifically the BC and CT subunits. Here, we review these recent findings and highlight key differences between the bacterial and eukaryotic isozymes with a view to establish those features that provide an opportunity for selective inhibition. Especially important are examples of highly selective small molecule inhibitors capable of differentiating between ACCs from different phyla. The implications for early stage antibiotic discovery projects, stemming from these studies, are discussed.
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Affiliation(s)
- S W Polyak
- School of Molecular and Biomedical Science, University of Adelaide, North Tce, Adelaide, South Australia 5005, Australia.
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22
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Dimerization of the bacterial biotin carboxylase subunit is required for acetyl coenzyme A carboxylase activity in vivo. J Bacteriol 2011; 194:72-8. [PMID: 22037404 DOI: 10.1128/jb.06309-11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acetyl coenzyme A (acteyl-CoA) carboxylase (ACC) is the first committed enzyme of the fatty acid synthesis pathway. Escherichia coli ACC is composed of four different proteins. The first enzymatic activity of the ACC complex, biotin carboxylase (BC), catalyzes the carboxylation of the protein-bound biotin moiety of another subunit with bicarbonate in an ATP-dependent reaction. Although BC is found as a dimer in cell extracts and the carboxylase activities of the two subunits of the dimer are interdependent, mutant BC proteins deficient in dimerization are reported to retain appreciable activity in vitro (Y. Shen, C. Y. Chou, G. G. Chang, and L. Tong, Mol. Cell 22:807-818, 2006). However, in vivo BC must interact with the other proteins of the complex, and thus studies of the isolated BC may not reflect the intracellular function of the enzyme. We have tested the abilities of three BC mutant proteins deficient in dimerization to support growth and report that the two BC proteins most deficient in dimerization fail to support growth unless expressed at high levels. In contrast, the wild-type protein supports growth at low expression levels. We conclude that BC must be dimeric to fulfill its physiological function.
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23
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Fang K, Zhao H, Sun C, Lam CMC, Chang S, Zhang K, Panda G, Godinho M, Martins dos Santos VAP, Wang J. Exploring the metabolic network of the epidemic pathogen Burkholderia cenocepacia J2315 via genome-scale reconstruction. BMC SYSTEMS BIOLOGY 2011; 5:83. [PMID: 21609491 PMCID: PMC3123600 DOI: 10.1186/1752-0509-5-83] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 05/25/2011] [Indexed: 11/10/2022]
Abstract
BACKGROUND Burkholderia cenocepacia is a threatening nosocomial epidemic pathogen in patients with cystic fibrosis (CF) or a compromised immune system. Its high level of antibiotic resistance is an increasing concern in treatments against its infection. Strain B. cenocepacia J2315 is the most infectious isolate from CF patients. There is a strong demand to reconstruct a genome-scale metabolic network of B. cenocepacia J2315 to systematically analyze its metabolic capabilities and its virulence traits, and to search for potential clinical therapy targets. RESULTS We reconstructed the genome-scale metabolic network of B. cenocepacia J2315. An iterative reconstruction process led to the establishment of a robust model, iKF1028, which accounts for 1,028 genes, 859 internal reactions, and 834 metabolites. The model iKF1028 captures important metabolic capabilities of B. cenocepacia J2315 with a particular focus on the biosyntheses of key metabolic virulence factors to assist in understanding the mechanism of disease infection and identifying potential drug targets. The model was tested through BIOLOG assays. Based on the model, the genome annotation of B. cenocepacia J2315 was refined and 24 genes were properly re-annotated. Gene and enzyme essentiality were analyzed to provide further insights into the genome function and architecture. A total of 45 essential enzymes were identified as potential therapeutic targets. CONCLUSIONS As the first genome-scale metabolic network of B. cenocepacia J2315, iKF1028 allows a systematic study of the metabolic properties of B. cenocepacia and its key metabolic virulence factors affecting the CF community. The model can be used as a discovery tool to design novel drugs against diseases caused by this notorious pathogen.
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Affiliation(s)
- Kechi Fang
- Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
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24
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So LH, Ghosh A, Zong C, Sepúlveda LA, Segev R, Golding I. General properties of transcriptional time series in Escherichia coli. Nat Genet 2011; 43:554-60. [PMID: 21532574 PMCID: PMC3102781 DOI: 10.1038/ng.821] [Citation(s) in RCA: 268] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 04/05/2011] [Indexed: 11/09/2022]
Abstract
Gene activity is described by the time-series of discrete, stochastic mRNA production events. This transcriptional time-series exhibits intermittent, bursty behavior. One consequence of this temporal intricacy is that gene expression can be tuned by varying different features of the time-series. What schemes for varying the transcriptional time-series are observed in the cell? Are the observed properties of these time-series optimized for cellular function? To address these questions, we characterize mRNA copy-number statistics at single-molecule resolution from multiple Escherichia coli promoters. We find that the degree of burstiness depends only on the gene expression level, while being independent of the details of gene regulation. The observed behavior is explained by the underlying variation in the duration of bursting events. Using information theory, we find that the properties of the transcriptional time series allow the cell to efficiently map the extracellular concentration of inducer molecules to intracellular levels of mRNA and proteins.
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Affiliation(s)
- Lok-Hang So
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
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25
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Handke P, Lynch SA, Gill RT. Application and engineering of fatty acid biosynthesis in Escherichia coli for advanced fuels and chemicals. Metab Eng 2011; 13:28-37. [DOI: 10.1016/j.ymben.2010.10.007] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 10/26/2010] [Accepted: 10/27/2010] [Indexed: 02/01/2023]
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26
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The switch regulating transcription of the Escherichia coli biotin operon does not require extensive protein-protein interactions. ACTA ACUST UNITED AC 2010; 17:11-7. [PMID: 20142036 DOI: 10.1016/j.chembiol.2009.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Revised: 11/22/2009] [Accepted: 12/01/2009] [Indexed: 11/22/2022]
Abstract
Transcription of the Escherichia coli biotin (bio) operon is regulated by BirA, a protein that is not only the repressor that regulates bio operon expression by DNA binding but also the enzyme that covalently attaches biotin to its cognate acceptor proteins. Binding of BirA to the bio operator requires dimerization of the protein that is triggered by BirA-catalyzed synthesis of biotinoyl-adenylate (bio-AMP), the obligatory intermediate of the attachment reaction. The current model postulates that the unmodified acceptor protein binds the monomeric BirA:bio-AMP complex and thereby blocks assembly (dimerization) of the form of BirA that binds DNA. We report that expression of fusion proteins that carry synthetic biotin-accepting peptide sequences was as effective as the natural acceptor protein in derepression of bio operon transcription. These peptide sequences have sequences that are remarkably dissimilar to that of the natural acceptor protein, and our data thus argue that the regulatory switch does not require the extensive protein-protein interactions postulated in the current model.
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27
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Kabiri M, Amoozegar MA, Tabebordbar M, Gilany K, Salekdeh GH. Effects of selenite and tellurite on growth, physiology, and proteome of a moderately halophilic bacterium. J Proteome Res 2009; 8:3098-108. [PMID: 19334765 DOI: 10.1021/pr900005h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We isolated a moderately halophilic bacterium with high level of tolerance to two toxic oxyanions, selenite and tellurite, from hypersaline soil in Garmsar, Iran. 16s rRNA sequence analysis revealed that the isolate, strain MAM, had 98% similarity with Halomonas elongate, and is closely related to other species of the genus Halomonas. We observed that the tolerance to tellurite and its removal increased significantly when both selenite and tellurite were added to the culture media, suggesting a positive synergism of selenite on tellurite tolerance and removal. We applied a proteomic approach to study the proteome response of Halomonas sp. strain MAM to selenite, tellurite, and selenite + tellurite. Out of approximately 800 protein spots detected on 2-DE gels, 208 spots were differentially expressed in response to at least one of treatments. Of them, 70 CBB stained spots were analyzed by MALDI TOF/TOF mass spectrometry, leading to identification of 36 proteins. Our results revealed that several mechanisms including fatty acid synthesis, energy production, cell transport, oxidative stress detoxification, DNA replication, transcription and translation contributed in bacterial response and/or adaptation. These results provided new insights into the general mechanisms on the tolerance of halophilic bacteria to these two toxic oxyanions and the use of them for bioremediation of contaminated saline soils and wastes discharge sites.
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Affiliation(s)
- Mahboubeh Kabiri
- Agricultural Biotechnology Research Institute of Iran, Karaj, Iran
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28
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The mosaic genome of Anaeromyxobacter dehalogenans strain 2CP-C suggests an aerobic common ancestor to the delta-proteobacteria. PLoS One 2008; 3:e2103. [PMID: 18461135 PMCID: PMC2330069 DOI: 10.1371/journal.pone.0002103] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Accepted: 03/19/2008] [Indexed: 11/29/2022] Open
Abstract
Anaeromyxobacter dehalogenans strain 2CP-C is a versaphilic delta-Proteobacterium distributed throughout many diverse soil and sediment environments. 16S rRNA gene phylogenetic analysis groups A. dehalogenans together with the myxobacteria, which have distinguishing characteristics including strictly aerobic metabolism, sporulation, fruiting body formation, and surface motility. Analysis of the 5.01 Mb strain 2CP-C genome substantiated that this organism is a myxobacterium but shares genotypic traits with the anaerobic majority of the delta-Proteobacteria (i.e., the Desulfuromonadales). Reflective of its respiratory versatility, strain 2CP-C possesses 68 genes coding for putative c-type cytochromes, including one gene with 40 heme binding motifs. Consistent with its relatedness to the myxobacteria, surface motility was observed in strain 2CP-C and multiple types of motility genes are present, including 28 genes for gliding, adventurous (A-) motility and 17 genes for type IV pilus-based motility (i.e., social (S-) motility) that all have homologs in Myxococcus xanthus. Although A. dehalogenans shares many metabolic traits with the anaerobic majority of the delta-Proteobacteria, strain 2CP-C grows under microaerophilic conditions and possesses detoxification systems for reactive oxygen species. Accordingly, two gene clusters coding for NADH dehydrogenase subunits and two cytochrome oxidase gene clusters in strain 2CP-C are similar to those in M. xanthus. Remarkably, strain 2CP-C possesses a third NADH dehydrogenase gene cluster and a cytochrome cbb3 oxidase gene cluster, apparently acquired through ancient horizontal gene transfer from a strictly anaerobic green sulfur bacterium. The mosaic nature of the A. dehalogenans strain 2CP-C genome suggests that the metabolically versatile, anaerobic members of the delta-Proteobacteria may have descended from aerobic ancestors with complex lifestyles.
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Abstract
Although the role of biotin in metabolic reactions has long been recognized, its influence on transcription has only recently been discovered. A key protein in biotin-mediated transcription regulation is the biotin protein ligase, the enzyme responsible for catalyzing covalent linkage of the vitamin to biotin-dependent carboxylases. In the biotin regulatory system of Escherichia coli, the best characterized of the biotin-sensing systems, the biotin protein ligase functions both as the biotinylating enzyme and as a transcription repressor. Detailed mechanistic studies of this system are reviewed. In addition, recent studies have revealed other biotin-sensing systems in organisms ranging from bacteria to humans. These systems and the central role of the biotin protein ligase in each are also reviewed.
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Affiliation(s)
- Dorothy Beckett
- Department of Chemistry and Biochemistry, College of Chemical and Life Sciences, University of Maryland, College Park, MD 20742, USA.
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