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Stahl K, Warneke R, Demann L, Bremenkamp R, Hormes B, Brock O, Stülke J, Rappsilber J. Modelling protein complexes with crosslinking mass spectrometry and deep learning. Nat Commun 2024; 15:7866. [PMID: 39251624 PMCID: PMC11383924 DOI: 10.1038/s41467-024-51771-2] [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: 09/08/2023] [Accepted: 08/16/2024] [Indexed: 09/11/2024] Open
Abstract
Scarcity of structural and evolutionary information on protein complexes poses a challenge to deep learning-based structure modelling. We integrate experimental distance restraints obtained by crosslinking mass spectrometry (MS) into AlphaFold-Multimer, by extending AlphaLink to protein complexes. Integrating crosslinking MS data substantially improves modelling performance on challenging targets, by helping to identify interfaces, focusing sampling, and improving model selection. This extends to single crosslinks from whole-cell crosslinking MS, opening the possibility of whole-cell structural investigations driven by experimental data. We demonstrate this by revealing the molecular basis of iron homoeostasis in Bacillus subtilis.
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Affiliation(s)
- Kolja Stahl
- Technische Universität Berlin, Chair of Bioanalytics, Berlin, Germany
| | - Robert Warneke
- Georg-August-Universität Göttingen, Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Göttingen, Germany
| | - Lorenz Demann
- Georg-August-Universität Göttingen, Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Göttingen, Germany
| | - Rica Bremenkamp
- Georg-August-Universität Göttingen, Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Göttingen, Germany
| | - Björn Hormes
- Georg-August-Universität Göttingen, Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Göttingen, Germany
| | - Oliver Brock
- Technische Universität Berlin, Robotics and Biology Laboratory, Berlin, Germany
- Science of Intelligence, Research Cluster of Excellence, Berlin, Germany
| | - Jörg Stülke
- Georg-August-Universität Göttingen, Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Göttingen, Germany.
| | - Juri Rappsilber
- Technische Universität Berlin, Chair of Bioanalytics, Berlin, Germany.
- Si-M/"Der Simulierte Mensch", a Science Framework of Technische Universität Berlin and Charité - Universitätsmedizin Berlin, Berlin, Germany.
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK.
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Warneke R, Herzberg C, Klein M, Elfmann C, Dittmann J, Feussner K, Feussner I, Stülke J. Coenzyme A biosynthesis in Bacillus subtilis: discovery of a novel precursor metabolite for salvage and its uptake system. mBio 2024:e0177224. [PMID: 39194188 DOI: 10.1128/mbio.01772-24] [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: 06/11/2024] [Accepted: 07/26/2024] [Indexed: 08/29/2024] Open
Abstract
The Gram-positive model bacterium Bacillus subtilis is used for many biotechnological applications, including the large-scale production of vitamins. For vitamin B5, a precursor for coenzyme A synthesis, there is so far no established fermentation process available, and the metabolic pathways that involve this vitamin are only partially understood. In this study, we have elucidated the complete pathways for the biosynthesis of pantothenate and coenzyme A in B. subtilis. Pantothenate can not only be synthesized but also be taken up from the medium. We have identified the enzymes and the transporter involved in the pantothenate biosynthesis and uptake. High-affinity vitamin B5 uptake in B. subtilis requires an ATP-driven energy coupling factor transporter with PanU (previously YhfU) as the substrate-specific subunit. Moreover, we have identified a salvage pathway for coenzyme A acquisition that acts on complex medium even in the absence of pantothenate synthesis. This pathway requires rewiring of sulfur metabolism resulting in the increased expression of a cysteine transporter. In the salvage pathway, the bacteria import cysteinopantetheine, a novel naturally occurring metabolite, using the cystine transport system TcyJKLMN. This work lays the foundation for the development of effective processes for vitamin B5 and coenzyme A production using B. subtilis. IMPORTANCE Vitamins are essential components of the diet of animals and humans. Vitamins are thus important targets for biotechnological production. While efficient fermentation processes have been developed for several vitamins, this is not the case for vitamin B5 (pantothenate), the precursor of coenzyme A. We have elucidated the complete pathway for coenzyme A biosynthesis in the biotechnological workhorse Bacillus subtilis. Moreover, a salvage pathway for coenzyme A synthesis was found in this study. Normally, this pathway depends on pantetheine; however, we observed activity of the salvage pathway on complex medium in mutants lacking the pantothenate biosynthesis pathway even in the absence of supplemented pantetheine. This required rewiring of metabolism by expressing a cystine transporter due to acquisition of mutations affecting the regulation of cysteine metabolism. This shows how the hidden "underground metabolism" can give rise to the rapid formation of novel metabolic pathways.
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Affiliation(s)
- Robert Warneke
- Department of General Microbiology, Institute for Microbiology & Genetics and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Christina Herzberg
- Department of General Microbiology, Institute for Microbiology & Genetics and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Moritz Klein
- Department of Plant Biochemistry, Albrecht-von-Haller Institute and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Christoph Elfmann
- Department of General Microbiology, Institute for Microbiology & Genetics and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Josi Dittmann
- Department of General Microbiology, Institute for Microbiology & Genetics and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Kirstin Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller Institute and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
- Service Unit for Metabolomics and Lipidomics, Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller Institute and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology & Genetics and Göttingen Center for Molecular Biosciences, University of Göttingen, Göttingen, Germany
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Put H, Gerstmans H, Vande Capelle H, Fauvart M, Michiels J, Masschelein J. Bacillus subtilis as a host for natural product discovery and engineering of biosynthetic gene clusters. Nat Prod Rep 2024; 41:1113-1151. [PMID: 38465694 DOI: 10.1039/d3np00065f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Covering: up to October 2023Many bioactive natural products are synthesized by microorganisms that are either difficult or impossible to cultivate under laboratory conditions, or that produce only small amounts of the desired compound. By transferring biosynthetic gene clusters (BGCs) into alternative host organisms that are more easily cultured and engineered, larger quantities can be obtained and new analogues with potentially improved biological activity or other desirable properties can be generated. Moreover, expression of cryptic BGCs in a suitable host can facilitate the identification and characterization of novel natural products. Heterologous expression therefore represents a valuable tool for natural product discovery and engineering as it allows the study and manipulation of their biosynthetic pathways in a controlled setting, enabling innovative applications. Bacillus is a genus of Gram-positive bacteria that is widely used in industrial biotechnology as a host for the production of proteins from diverse origins, including enzymes and vaccines. However, despite numerous successful examples, Bacillus species remain underexploited as heterologous hosts for the expression of natural product BGCs. Here, we review important advantages that Bacillus species offer as expression hosts, such as high secretion capacity, natural competence for DNA uptake, and the increasing availability of a wide range of genetic tools for gene expression and strain engineering. We evaluate different strain optimization strategies and other critical factors that have improved the success and efficiency of heterologous natural product biosynthesis in B. subtilis. Finally, future perspectives for using B. subtilis as a heterologous host are discussed, identifying research gaps and promising areas that require further exploration.
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Affiliation(s)
- Hanne Put
- Centre of Microbial and Plant Genetics, KU Leuven, 3001 Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
| | - Hans Gerstmans
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
- Laboratory for Biomolecular Discovery & Engineering, KU Leuven, 3001 Leuven, Belgium
- Biosensors Group, KU Leuven, 3001 Leuven, Belgium
| | - Hanne Vande Capelle
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
- Laboratory for Biomolecular Discovery & Engineering, KU Leuven, 3001 Leuven, Belgium
| | - Maarten Fauvart
- Centre of Microbial and Plant Genetics, KU Leuven, 3001 Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
- imec, 3001 Leuven, Belgium
| | - Jan Michiels
- Centre of Microbial and Plant Genetics, KU Leuven, 3001 Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
| | - Joleen Masschelein
- VIB-KU Leuven Center for Microbiology, Flanders Institute for Biotechnology, 3001 Leuven, Belgium.
- Laboratory for Biomolecular Discovery & Engineering, KU Leuven, 3001 Leuven, Belgium
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Warneke R, Herzberg C, Daniel R, Hormes B, Stülke J. Control of three-carbon amino acid homeostasis by promiscuous importers and exporters in Bacillus subtilis: role of the "sleeping beauty" amino acid exporters. mBio 2024; 15:e0345623. [PMID: 38470260 PMCID: PMC11005379 DOI: 10.1128/mbio.03456-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/13/2024] [Indexed: 03/13/2024] Open
Abstract
The Gram-positive model bacterium Bacillus subtilis can acquire amino acids by import, de novo biosynthesis, or degradation of proteins and peptides. The accumulation of several amino acids inhibits the growth of B. subtilis, probably due to misincorporation into cellular macromolecules such as proteins or peptidoglycan or due to interference with other amino acid biosynthetic pathways. Here, we studied the adaptation of B. subtilis to toxic concentrations of the three-carbon amino acids L-alanine, β-alanine, and 2,3-diaminopropionic acid, as well as the two-carbon amino acid glycine. Resistance to the non-proteinogenic amino acid β-alanine, which is a precursor for coenzyme A biosynthesis, is achieved by mutations that either activate a cryptic amino acid exporter, AexA (previously YdeD), or inactivate the amino acid importers AimA, AimB (previously YbxG), and BcaP. The aexA gene is very poorly expressed under most conditions studied. However, mutations affecting the transcription factor AerA (previously YdeC) can result in strong constitutive aexA expression. AexA is the first characterized member of a group of amino acid exporters in B. subtilis, which are all very poorly expressed. Therefore, we suggest to call this group "sleeping beauty amino acid exporters." 2,3-Diaminopropionic acid can also be exported by AexA, and this amino acid also seems to be a natural substrate of AerA/AexA, as it can cause a slight but significant induction of aexA expression, and AexA also provides some natural resistance toward 2,3-diaminopropionic acid. Moreover, our work shows how low-specificity amino acid transporters contribute to amino acid homeostasis in B. subtilis.IMPORTANCEEven though Bacillus subtilis is one of the most-studied bacteria, amino acid homeostasis in this organism is not fully understood. We have identified import and export systems for the C2 and C3 amino acids. Our work demonstrates that the responsible amino acid permeases contribute in a rather promiscuitive way to amino acid uptake. In addition, we have discovered AexA, the first member of a group of very poorly expressed amino acid exporters in B. subtilis that we call "sleeping beauty amino acid exporters." The expression of these transporters is typically triggered by mutations in corresponding regulator genes that are acquired upon exposure to toxic amino acids. These exporters are ubiquitous in all domains of life. It is tempting to speculate that many of them are not expressed until the cells experience selective pressure by toxic compounds, and they protect the cells from rare but potentially dangerous encounters with such compounds.
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Affiliation(s)
- Robert Warneke
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| | - Christina Herzberg
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| | - Richard Daniel
- Center for Bacterial Cell Biology, Biosciences Institute, Medical Faculty, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Björn Hormes
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University, Göttingen, Germany
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Meißner J, Königshof M, Wrede K, Warneke R, Mardoukhi MSY, Commichau FM, Stülke J. Control of asparagine homeostasis in Bacillus subtilis: identification of promiscuous amino acid importers and exporters. J Bacteriol 2024; 206:e0042023. [PMID: 38193659 PMCID: PMC10882977 DOI: 10.1128/jb.00420-23] [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: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 01/10/2024] Open
Abstract
The Gram-positive model bacterium B. subtilis is able to import all proteinogenic amino acids from the environment as well as to synthesize them. However, the players involved in the acquisition of asparagine have not yet been identified for this bacterium. In this work, we used d-asparagine as a toxic analog of l-asparagine to identify asparagine transporters. This revealed that d- but not l-asparagine is taken up by the malate/lactate antiporter MleN. Specific strains that are sensitive to the presence of l-asparagine due to the lack of the second messenger cyclic di-AMP or due to the intracellular accumulation of this amino acid were used to isolate and characterize suppressor mutants that were resistant to the presence of otherwise growth-inhibiting concentrations of l-asparagine. These screens identified the broad-spectrum amino acid importers AimA and BcaP as responsible for the acquisition of l-asparagine. The amino acid exporter AzlCD allows detoxification of l-asparagine in addition to 4-azaleucine and histidine. This work supports the idea that amino acids are often transported by promiscuous importers and exporters. However, our work also shows that even stereo-enantiomeric amino acids do not necessarily use the same transport systems.IMPORTANCETransport of amino acid is a poorly studied function in many bacteria, including the model organism Bacillus subtilis. The identification of transporters is hampered by the redundancy of transport systems for most amino acids as well as by the poor specificity of the transporters. Here, we apply several strategies to use the growth-inhibitive effect of many amino acids under defined conditions to isolate suppressor mutants that exhibit either reduced uptake or enhanced export of asparagine, resulting in the identification of uptake and export systems for l-asparagine. The approaches used here may be useful for the identification of transporters for other amino acids both in B. subtilis and in other bacteria.
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Affiliation(s)
- Janek Meißner
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Manuel Königshof
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Katrin Wrede
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Robert Warneke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | | | - Fabian M. Commichau
- FG Molecular Microbiology, Institute for Biology, University of Hohenheim, Stuttgart, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
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6
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Wicke D, Neumann P, Gößringer M, Chernev A, Davydov S, Poehlein A, Daniel R, Urlaub H, Hartmann R, Ficner R, Stülke J. The previously uncharacterized RnpM (YlxR) protein modulates the activity of ribonuclease P in Bacillus subtilis in vitro. Nucleic Acids Res 2024; 52:1404-1419. [PMID: 38050972 PMCID: PMC10853771 DOI: 10.1093/nar/gkad1171] [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: 07/28/2023] [Accepted: 11/22/2023] [Indexed: 12/07/2023] Open
Abstract
Even though Bacillus subtilis is one of the most studied organisms, no function has been identified for about 20% of its proteins. Among these unknown proteins are several RNA- and ribosome-binding proteins suggesting that they exert functions in cellular information processing. In this work, we have investigated the RNA-binding protein YlxR. This protein is widely conserved in bacteria and strongly constitutively expressed in B. subtilis suggesting an important function. We have identified the RNA subunit of the essential RNase P as the binding partner of YlxR. The main activity of RNase P is the processing of 5' ends of pre-tRNAs. In vitro processing assays demonstrated that the presence of YlxR results in reduced RNase P activity. Chemical cross-linking studies followed by in silico docking analysis and experiments with site-directed mutant proteins suggest that YlxR binds to the region of the RNase P RNA that is important for binding and cleavage of the pre-tRNA substrate. We conclude that the YlxR protein is a novel interaction partner of the RNA subunit of RNase P that serves to finetune RNase P activity to ensure appropriate amounts of mature tRNAs for translation. We rename the YlxR protein RnpM for RNase P modulator.
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Affiliation(s)
- Dennis Wicke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Piotr Neumann
- Department of Molecular Structural Biology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Markus Gößringer
- Institute for the Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Aleksandar Chernev
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Swetlana Davydov
- Institute for the Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology & Göttingen Genomics Laboratory, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Institute of Clinical Chemistry, GZMB, University Medical Centre Göttingen, Germany
- Cluster of Excellence “Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells” (MBExC), Georg-August-University Göttingen, Germany
| | - Roland K Hartmann
- Institute for the Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Göttingen, Germany
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Voogdt CGP, Tripathi S, Bassler SO, McKeithen-Mead SA, Guiberson ER, Koumoutsi A, Bravo AM, Buie C, Zimmermann M, Sonnenburg JL, Typas A, Deutschbauer AM, Shiver AL, Huang KC. Randomly barcoded transposon mutant libraries for gut commensals II: Applying libraries for functional genetics. Cell Rep 2024; 43:113519. [PMID: 38142398 DOI: 10.1016/j.celrep.2023.113519] [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: 07/17/2023] [Revised: 10/22/2023] [Accepted: 11/14/2023] [Indexed: 12/26/2023] Open
Abstract
The critical role of the intestinal microbiota in human health and disease is well recognized. Nevertheless, there are still large gaps in our understanding of the functions and mechanisms encoded in the genomes of most members of the gut microbiota. Genome-scale libraries of transposon mutants are a powerful tool to help us address this gap. Recent advances in barcoded transposon mutagenesis have dramatically lowered the cost of mutant fitness determination in hundreds of in vitro and in vivo experimental conditions. In an accompanying review, we discuss recent advances and caveats for the construction of pooled and arrayed barcoded transposon mutant libraries in human gut commensals. In this review, we discuss how these libraries can be used across a wide range of applications, the technical aspects involved, and expectations for such screens.
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Affiliation(s)
- Carlos Geert Pieter Voogdt
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Structural and Computational Biology Unit, EMBL, Heidelberg, Germany
| | - Surya Tripathi
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Stefan Oliver Bassler
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, Grabengasse 1, 69117 Heidelberg, Germany
| | - Saria A McKeithen-Mead
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Emma R Guiberson
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Alexandra Koumoutsi
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Afonso Martins Bravo
- Department of Fundamental Microbiology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Cullen Buie
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Justin L Sonnenburg
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Athanasios Typas
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Structural and Computational Biology Unit, EMBL, Heidelberg, Germany.
| | - Adam M Deutschbauer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Anthony L Shiver
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
| | - Kerwyn Casey Huang
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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8
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Herzberg C, Meißner J, Warneke R, Stülke J. The many roles of cyclic di-AMP to control the physiology of Bacillus subtilis. MICROLIFE 2023; 4:uqad043. [PMID: 37954098 PMCID: PMC10636490 DOI: 10.1093/femsml/uqad043] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/21/2023] [Accepted: 10/19/2023] [Indexed: 11/14/2023]
Abstract
The dinucleotide cyclic di-AMP (c-di-AMP) is synthesized as a second messenger in the Gram-positive model bacterium Bacillus subtilis as well as in many bacteria and archaea. Bacillus subtilis possesses three diadenylate cyclases and two phosphodiesterases that synthesize and degrade the molecule, respectively. Among the second messengers, c-di-AMP is unique since it is essential for B. subtilis on the one hand but toxic upon accumulation on the other. This role as an "essential poison" is related to the function of c-di-AMP in the control of potassium homeostasis. C-di-AMP inhibits the expression and activity of potassium uptake systems by binding to riboswitches and transporters and activates the activity of potassium exporters. In this way, c-di-AMP allows the adjustment of uptake and export systems to achieve a balanced intracellular potassium concentration. C-di-AMP also binds to two dedicated signal transduction proteins, DarA and DarB. Both proteins seem to interact with other proteins in their apo state, i.e. in the absence of c-di-AMP. For DarB, the (p)ppGpp synthetase/hydrolase Rel and the pyruvate carboxylase PycA have been identified as targets. The interactions trigger the synthesis of the alarmone (p)ppGpp and of the acceptor molecule for the citric acid cycle, oxaloacetate, respectively. In the absence of c-di-AMP, many amino acids inhibit the growth of B. subtilis. This feature can be used to identify novel players in amino acid homeostasis. In this review, we discuss the different functions of c-di-AMP and their physiological relevance.
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Affiliation(s)
- Christina Herzberg
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Janek Meißner
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Robert Warneke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, GZMB, Georg-August-University Göttingen, Grisebachstr. 8, 37077 Göttingen, Germany
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9
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Winkler KR, Mizrahi V, Warner DF, De Wet TJ. High-throughput functional genomics: A (myco)bacterial perspective. Mol Microbiol 2023; 120:141-158. [PMID: 37278255 PMCID: PMC10953053 DOI: 10.1111/mmi.15103] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/06/2023] [Accepted: 05/21/2023] [Indexed: 06/07/2023]
Abstract
Advances in sequencing technologies have enabled unprecedented insights into bacterial genome composition and dynamics. However, the disconnect between the rapid acquisition of genomic data and the (much slower) confirmation of inferred genetic function threatens to widen unless techniques for fast, high-throughput functional validation can be applied at scale. This applies equally to Mycobacterium tuberculosis, the leading infectious cause of death globally and a pathogen whose genome, despite being among the first to be sequenced two decades ago, still contains many genes of unknown function. Here, we summarize the evolution of bacterial high-throughput functional genomics, focusing primarily on transposon (Tn)-based mutagenesis and the construction of arrayed mutant libraries in diverse bacterial systems. We also consider the contributions of CRISPR interference as a transformative technique for probing bacterial gene function at scale. Throughout, we situate our analysis within the context of functional genomics of mycobacteria, focusing specifically on the potential to yield insights into M. tuberculosis pathogenicity and vulnerabilities for new drug and regimen development. Finally, we offer suggestions for future approaches that might be usefully applied in elucidating the complex cellular biology of this major human pathogen.
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Affiliation(s)
- Kristy R. Winkler
- Molecular Mycobacteriology Research Unit and DSI/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular MedicineUniversity of Cape TownRondeboschSouth Africa
| | - Valerie Mizrahi
- Molecular Mycobacteriology Research Unit and DSI/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular MedicineUniversity of Cape TownRondeboschSouth Africa
- Wellcome Centre for Infectious Diseases Research in AfricaUniversity of Cape TownRondeboschSouth Africa
| | - Digby F. Warner
- Molecular Mycobacteriology Research Unit and DSI/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular MedicineUniversity of Cape TownRondeboschSouth Africa
- Wellcome Centre for Infectious Diseases Research in AfricaUniversity of Cape TownRondeboschSouth Africa
| | - Timothy J. De Wet
- Molecular Mycobacteriology Research Unit and DSI/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular MedicineUniversity of Cape TownRondeboschSouth Africa
- Wellcome Centre for Infectious Diseases Research in AfricaUniversity of Cape TownRondeboschSouth Africa
- Department of Integrative Biomedical SciencesUniversity of Cape TownRondeboschSouth Africa
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10
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Stülke J, Grüppen A, Bramkamp M, Pelzer S. Bacillus subtilis, a Swiss Army Knife in Science and Biotechnology. J Bacteriol 2023; 205:e0010223. [PMID: 37140386 PMCID: PMC10210981 DOI: 10.1128/jb.00102-23] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023] Open
Abstract
Next to Escherichia coli, Bacillus subtilis is the most studied and best understood organism that also serves as a model for many important pathogens. Due to its ability to form heat-resistant spores that can germinate even after very long periods of time, B. subtilis has attracted much scientific interest. Another feature of B. subtilis is its genetic competence, a developmental state in which B. subtilis actively takes up exogenous DNA. This makes B. subtilis amenable to genetic manipulation and investigation. The bacterium was one of the first with a fully sequenced genome, and it has been subject to a wide variety of genome- and proteome-wide studies that give important insights into many aspects of the biology of B. subtilis. Due to its ability to secrete large amounts of proteins and to produce a wide range of commercially interesting compounds, B. subtilis has become a major workhorse in biotechnology. Here, we review the development of important aspects of the research on B. subtilis with a specific focus on its cell biology and biotechnological and practical applications from vitamin production to concrete healing. The intriguing complexity of the developmental programs of B. subtilis, paired with the availability of sophisticated tools for genetic manipulation, positions it at the leading edge for discovering new biological concepts and deepening our understanding of the organization of bacterial cells.
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Affiliation(s)
- Jörg Stülke
- Department of General Microbiology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | | | - Marc Bramkamp
- Institute for General Microbiology, Christian-Albrechts-University Kiel, Kiel, Germany
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11
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Elfmann C, Stülke J. PAE viewer: a webserver for the interactive visualization of the predicted aligned error for multimer structure predictions and crosslinks. Nucleic Acids Res 2023:7151339. [PMID: 37140053 DOI: 10.1093/nar/gkad350] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 04/14/2023] [Accepted: 04/21/2023] [Indexed: 05/05/2023] Open
Abstract
The development of AlphaFold for protein structure prediction has opened a new era in structural biology. This is even more the case for AlphaFold-Multimer for the prediction of protein complexes. The interpretation of these predictions has become more important than ever, but it is difficult for the non-specialist. While an evaluation of the prediction quality is provided for monomeric protein predictions by the AlphaFold Protein Structure Database, such a tool is missing for predicted complex structures. Here, we present the PAE Viewer webserver (http://www.subtiwiki.uni-goettingen.de/v4/paeViewerDemo), an online tool for the integrated visualization of predicted protein complexes using a 3D structure display combined with an interactive representation of the Predicted Aligned Error (PAE). This metric allows an estimation of the quality of the prediction. Importantly, our webserver also allows the integration of experimental cross-linking data which helps to interpret the reliability of the structure predictions. With the PAE Viewer, the user obtains a unique online tool which for the first time allows the intuitive evaluation of the PAE for protein complex structure predictions with integrated crosslinks.
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Affiliation(s)
- Christoph Elfmann
- Department of General Microbiology, Georg-August-University Göttingen, GZMB, 37077 Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, Georg-August-University Göttingen, GZMB, 37077 Göttingen, Germany
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