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Saggu SK, Nath A, Kumar S. Myxobacteria: biology and bioactive secondary metabolites. Res Microbiol 2023; 174:104079. [PMID: 37169232 DOI: 10.1016/j.resmic.2023.104079] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 04/22/2023] [Accepted: 05/04/2023] [Indexed: 05/13/2023]
Abstract
Myxobacteria are Gram-negative eubacteria and they thrive in a variety of habitats including soil rich in organic matter, rotting wood, animal dung and marine environment. Myxobacteria are a promising source of new compounds associated with diverse bioactive spectrum and unique mode of action. The genome information of myxobacteria has revealed many orphan biosynthetic pathways indicating that these bacteria can be the source of several novel natural products. In this review, we highlight the biology of myxobacteria with emphasis on their habitat, life cycle, isolation methods and enlist all the bioactive secondary metabolites purified till date and their mode of action.
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Affiliation(s)
- Sandeep Kaur Saggu
- Department of Biotechnology, Kanya Maha Vidyalaya, Jalandhar, Punjab, India - 144004.
| | - Amar Nath
- University Centre of Excellence in Research, Baba Farid University of Health Sciences, Faridkot, Punjab India 151203.
| | - Shiv Kumar
- Guru Gobind Singh Medical College, Baba Farid University of Health Sciences, Faridkot, Punjab India 151203.
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Islam ST, Jolivet NY, Cuzin C, Belgrave AM, My L, Fleuchot B, Faure LM, Mahanta U, Kezzo AA, Saïdi F, Sharma G, Fiche JB, Bratton BP, Herrou J, Nollmann M, Shaevitz JW, Durand E, Mignot T. Unmasking of the von Willebrand A-domain surface adhesin CglB at bacterial focal adhesions mediates myxobacterial gliding motility. SCIENCE ADVANCES 2023; 9:eabq0619. [PMID: 36812310 PMCID: PMC9946355 DOI: 10.1126/sciadv.abq0619] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 01/24/2023] [Indexed: 06/18/2023]
Abstract
The predatory deltaproteobacterium Myxococcus xanthus uses a helically-trafficked motor at bacterial focal-adhesion (bFA) sites to power gliding motility. Using total internal reflection fluorescence and force microscopies, we identify the von Willebrand A domain-containing outer-membrane (OM) lipoprotein CglB as an essential substratum-coupling adhesin of the gliding transducer (Glt) machinery at bFAs. Biochemical and genetic analyses reveal that CglB localizes to the cell surface independently of the Glt apparatus; once there, it is recruited by the OM module of the gliding machinery, a heteroligomeric complex containing the integral OM β barrels GltA, GltB, and GltH, as well as the OM protein GltC and OM lipoprotein GltK. This Glt OM platform mediates the cell-surface accessibility and retention of CglB by the Glt apparatus. Together, these data suggest that the gliding complex promotes regulated surface exposure of CglB at bFAs, thus explaining the manner by which contractile forces exerted by inner-membrane motors are transduced across the cell envelope to the substratum.
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Affiliation(s)
- Salim T. Islam
- Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Santé Biotechnologie, Université du Québec, Institut Pasteur International Network, Laval, QC H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Laval, QC G1V 0A6, Canada
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Nicolas Y. Jolivet
- Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Santé Biotechnologie, Université du Québec, Institut Pasteur International Network, Laval, QC H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Laval, QC G1V 0A6, Canada
| | - Clémence Cuzin
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Akeisha M. Belgrave
- Integrated Sciences Program, Harrisburg University of Science and Technology, Harrisburg, PA 17101, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Laetitia My
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Betty Fleuchot
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Laura M. Faure
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Utkarsha Mahanta
- Institute of Bioinformatics and Applied Biotechnology, Electronic City, Bengaluru-560100, Karnataka, India
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana-502284, India
| | - Ahmad A. Kezzo
- Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Santé Biotechnologie, Université du Québec, Institut Pasteur International Network, Laval, QC H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Laval, QC G1V 0A6, Canada
| | - Fares Saïdi
- Institut National de la Recherche Scientifique (INRS), Centre Armand-Frappier Santé Biotechnologie, Université du Québec, Institut Pasteur International Network, Laval, QC H7V 1B7, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Laval, QC G1V 0A6, Canada
| | - Gaurav Sharma
- Institute of Bioinformatics and Applied Biotechnology, Electronic City, Bengaluru-560100, Karnataka, India
- Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana-502284, India
| | - Jean-Bernard Fiche
- Centre de Biochimie Structurale, CNRS UMR5048, INSERM U1054, 34090 Montpellier, France
| | - Benjamin P. Bratton
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, TN 37232, USA
| | - Julien Herrou
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Marcelo Nollmann
- Centre de Biochimie Structurale, CNRS UMR5048, INSERM U1054, 34090 Montpellier, France
| | - Joshua W. Shaevitz
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08540, USA
| | - Eric Durand
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
| | - Tâm Mignot
- Laboratoire de Chimie Bactérienne, CNRS - Université Aix-Marseille UMR7283, Institut de Microbiologie de la Méditerranée, 13009 Marseille, France
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Myxobacterial Genomics and Post-Genomics: A Review of Genome Biology, Genome Sequences and Related 'Omics Studies. Microorganisms 2021; 9:microorganisms9102143. [PMID: 34683464 PMCID: PMC8538405 DOI: 10.3390/microorganisms9102143] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 11/27/2022] Open
Abstract
Myxobacteria are fascinating and complex microbes. They prey upon other members of the soil microbiome by secreting antimicrobial proteins and metabolites, and will undergo multicellular development if starved. The genome sequence of the model myxobacterium Myxococcus xanthus DK1622 was published in 2006 and 15 years later, 163 myxobacterial genome sequences have now been made public. This explosion in genomic data has enabled comparative genomics analyses to be performed across the taxon, providing important insights into myxobacterial gene conservation and evolution. The availability of myxobacterial genome sequences has allowed system-wide functional genomic investigations into entire classes of genes. It has also enabled post-genomic technologies to be applied to myxobacteria, including transcriptome analyses (microarrays and RNA-seq), proteome studies (gel-based and gel-free), investigations into protein–DNA interactions (ChIP-seq) and metabolism. Here, we review myxobacterial genome sequencing, and summarise the insights into myxobacterial biology that have emerged as a result. We also outline the application of functional genomics and post-genomic approaches in myxobacterial research, highlighting important findings to emerge from seminal studies. The review also provides a comprehensive guide to the genomic datasets available in mid-2021 for myxobacteria (including 24 genomes that we have sequenced and which are described here for the first time).
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Pal S, Sharma G, Subramanian S. Complete genome sequence and identification of polyunsaturated fatty acid biosynthesis genes of the myxobacterium Minicystis rosea DSM 24000 T. BMC Genomics 2021; 22:655. [PMID: 34511070 PMCID: PMC8436480 DOI: 10.1186/s12864-021-07955-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/23/2021] [Indexed: 11/17/2022] Open
Abstract
Background Myxobacteria harbor numerous biosynthetic gene clusters that can produce a diverse range of secondary metabolites. Minicystis rosea DSM 24000T is a soil-dwelling myxobacterium belonging to the suborderSorangiineae and family Polyangiaceae and is known to produce various secondary metabolites as well as polyunsaturated fatty acids (PUFAs). Here, we use whole-genome sequencing to explore the diversity of biosynthetic gene clusters in M. rosea. Results Using PacBio sequencing technology, we assembled the 16.04 Mbp complete genome of M. rosea DSM 24000T, the largest bacterial genome sequenced to date. About 44% of its coding potential represents paralogous genes predominantly associated with signal transduction, transcriptional regulation, and protein folding. These genes are involved in various essential functions such as cellular organization, diverse niche adaptation, and bacterial cooperation, and enable social behavior like gliding motility, sporulation, and predation, typical of myxobacteria. A profusion of eukaryotic-like kinases (353) and an elevated ratio of phosphatases (8.2/1) in M. rosea as compared to other myxobacteria suggest gene duplication as one of the primary modes of genome expansion. About 7.7% of the genes are involved in the biosynthesis of a diverse array of secondary metabolites such as polyketides, terpenes, and bacteriocins. Phylogeny of the genes involved in PUFA biosynthesis (pfa) together with the conserved synteny of the complete pfa gene cluster suggests acquisition via horizontal gene transfer from Actinobacteria. Conclusion Overall, this study describes the complete genome sequence of M. rosea, comparative genomic analysis to explore the putative reasons for its large genome size, and explores the secondary metabolite potential, including the biosynthesis of polyunsaturated fatty acids. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07955-x.
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Affiliation(s)
- Shilpee Pal
- CSIR-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India
| | - Gaurav Sharma
- CSIR-Institute of Microbial Technology (CSIR-IMTECH), Chandigarh, India.,Institute of Bioinformatics and Applied Biotechnology (IBAB), Bengaluru, Karnataka, India
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Islam ST, Vergara Alvarez I, Saïdi F, Guiseppi A, Vinogradov E, Sharma G, Espinosa L, Morrone C, Brasseur G, Guillemot JF, Benarouche A, Bridot JL, Ravicoularamin G, Cagna A, Gauthier C, Singer M, Fierobe HP, Mignot T, Mauriello EMF. Modulation of bacterial multicellularity via spatio-specific polysaccharide secretion. PLoS Biol 2020; 18:e3000728. [PMID: 32516311 PMCID: PMC7310880 DOI: 10.1371/journal.pbio.3000728] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 06/23/2020] [Accepted: 05/21/2020] [Indexed: 11/21/2022] Open
Abstract
The development of multicellularity is a key evolutionary transition allowing for differentiation of physiological functions across a cell population that confers survival benefits; among unicellular bacteria, this can lead to complex developmental behaviors and the formation of higher-order community structures. Herein, we demonstrate that in the social δ-proteobacterium Myxococcus xanthus, the secretion of a novel biosurfactant polysaccharide (BPS) is spatially modulated within communities, mediating swarm migration as well as the formation of multicellular swarm biofilms and fruiting bodies. BPS is a type IV pilus (T4P)-inhibited acidic polymer built of randomly acetylated β-linked tetrasaccharide repeats. Both BPS and exopolysaccharide (EPS) are produced by dedicated Wzx/Wzy-dependent polysaccharide-assembly pathways distinct from that responsible for spore-coat assembly. While EPS is preferentially produced at the lower-density swarm periphery, BPS production is favored in the higher-density swarm interior; this is consistent with the former being known to stimulate T4P retraction needed for community expansion and a function for the latter in promoting initial cell dispersal. Together, these data reveal the central role of secreted polysaccharides in the intricate behaviors coordinating bacterial multicellularity. A study of the social bacterium Myxococcus xanthus reveals that the bacteria preferentially secrete specific polysaccharides within distinct zones of a swarm to facilitate spreading across a surface.
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Affiliation(s)
- Salim T. Islam
- Armand Frappier Health & Biotechnology Research Centre, Institut National de la Recherche Scientifique, Université du Québec, Institut Pasteur International Network, Laval, Québec, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Québec, Québec, Canada
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
- * E-mail: (STI); (EMFM)
| | - Israel Vergara Alvarez
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Fares Saïdi
- Armand Frappier Health & Biotechnology Research Centre, Institut National de la Recherche Scientifique, Université du Québec, Institut Pasteur International Network, Laval, Québec, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Québec, Québec, Canada
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Annick Guiseppi
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Evgeny Vinogradov
- Human Health Therapeutics Portfolio, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Gaurav Sharma
- Department of Microbiology and Molecular Genetics, University of California–Davis, Davis, California, United States of America
- Institute of Bioinformatics and Applied Biotechnology, Electronic City, Bengaluru, Karnataka, India
| | - Leon Espinosa
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Castrese Morrone
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Gael Brasseur
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | | | | | | | - Gokulakrishnan Ravicoularamin
- Armand Frappier Health & Biotechnology Research Centre, Institut National de la Recherche Scientifique, Université du Québec, Institut Pasteur International Network, Laval, Québec, Canada
| | - Alain Cagna
- Teclis Scientific, Civrieux d’Azergue, France
| | - Charles Gauthier
- Armand Frappier Health & Biotechnology Research Centre, Institut National de la Recherche Scientifique, Université du Québec, Institut Pasteur International Network, Laval, Québec, Canada
| | - Mitchell Singer
- Department of Microbiology and Molecular Genetics, University of California–Davis, Davis, California, United States of America
| | - Henri-Pierre Fierobe
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Tâm Mignot
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Emilia M. F. Mauriello
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
- * E-mail: (STI); (EMFM)
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Whitfield DL, Sharma G, Smaldone GT, Singer M. Peripheral rods: a specialized developmental cell type in Myxococcus xanthus. Genomics 2019; 112:1588-1597. [PMID: 31605730 DOI: 10.1016/j.ygeno.2019.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 08/13/2019] [Accepted: 09/11/2019] [Indexed: 01/08/2023]
Abstract
In response to nutrient deprivation, the ubiquitous Gram-negative soil bacterium Myxococcus xanthus undergoes a well-characterized developmental response, resulting in the formation of a multicellular fruiting body. The center of the fruiting body consists of myxospores; surrounding this structure are rod-shaped peripheral cells. Unlike spores, the peripheral rods are a metabolically active cell type that inhabits nutrient-deprived environments. The survival characteristics exhibited by peripheral rods, protection from oxidative stress and heat shock, are common survival characteristics exhibited by cells in stationary phase including modifications to morphology and metabolism. Vegetative M. xanthus cells undergo a number of physiological changes during the transition into stationary phase similar to other proteobacteria. In M. xanthus, stationary-phase cells are not considered a component of the developmental response and occur when cells are grown on nutrient-rich plates or in dispersed aqueous media. However, this cell type is not routinely studied and little of its physiology is known. Similarities between these two stress-induced cell types led to the question of whether peripheral rods are actually a distinct developmental cell type or simply cells in stationary phase. In this study, we examine the transcriptome of peripheral rods and its relationship to development. This work demonstrates that peripheral rods are in fact a distinct developmentally differentiated cell type. Although peripheral rods and stationary phase cells display similar characteristics, each transcriptomic pattern is unique and quite different from that of any other M. xanthus cell type.
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Affiliation(s)
- Damion L Whitfield
- Dept. of Microbiology and Molecular Genetics, University of California, Davis, CA, USA.
| | - Gaurav Sharma
- Dept. of Microbiology and Molecular Genetics, University of California, Davis, CA, USA
| | - Gregory T Smaldone
- Dept. of Microbiology and Molecular Genetics, University of California, Davis, CA, USA
| | - Mitchell Singer
- Dept. of Microbiology and Molecular Genetics, University of California, Davis, CA, USA.
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Klenk JM, Dubiel P, Sharma M, Grogan G, Hauer B. Characterization and structure-guided engineering of the novel versatile terpene monooxygenase CYP109Q5 from Chondromyces apiculatus DSM436. Microb Biotechnol 2019; 12:377-391. [PMID: 30592153 PMCID: PMC6389848 DOI: 10.1111/1751-7915.13354] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/16/2018] [Accepted: 11/17/2018] [Indexed: 01/12/2023] Open
Abstract
One of the major challenges in chemical synthesis is the selective oxyfunctionalization of non-activated C-H bonds, which can be enabled by biocatalysis using cytochrome P450 monooxygenases. In this study, we report on the characterization of the versatile CYP109Q5 from Chondromyces apiculatus DSM436, which is able to functionalize a wide range of substrates (terpenes, steroids and drugs), including the ring of β-ionone in non-allylic positions. The crystal structure of CYP109Q5 revealed flexibility within the active site pocket that permitted the accommodation of bulky substrates, and enabled a structure-guided approach to engineering the enzyme. Some variants of CYP109Q5 displayed a switch in selectivity towards the non-allylic positions of β-ionone, allowing the simultaneous production of 2- and 3-hydroxy-β-ionone, which are chemically challenging to synthesize and are important precursors for carotenoid synthesis. An efficient whole-cell system finally enabled the production of up to 0.5 g l-1 hydroxylated products of β-ionone; this system can be applied to product identification in further biotransformations. Overall, CYP109Q5 proved to be highly evolvable and active. The studies in this work demonstrate that, using rational mutagenesis, the highly versatile CYP109Q5 generalist can be progressively evolved to be an industrially valuable specialist for the synthesis of specific products.
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Affiliation(s)
- Jan M. Klenk
- Institute of Biochemistry and Technical BiochemistryDepartment of Technical BiochemistryUniversity of StuttgartAllmandring 3170569StuttgartGermany
| | - Paulina Dubiel
- Department of ChemistryUniversity of YorkHeslingtonYorkYO10 5DDUK
| | - Mahima Sharma
- Department of ChemistryUniversity of YorkHeslingtonYorkYO10 5DDUK
| | - Gideon Grogan
- Department of ChemistryUniversity of YorkHeslingtonYorkYO10 5DDUK
| | - Bernhard Hauer
- Institute of Biochemistry and Technical BiochemistryDepartment of Technical BiochemistryUniversity of StuttgartAllmandring 3170569StuttgartGermany
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In silico characterization of a novel putative aerotaxis chemosensory system in the myxobacterium, Corallococcus coralloides. BMC Genomics 2018; 19:757. [PMID: 30340510 PMCID: PMC6194562 DOI: 10.1186/s12864-018-5151-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 10/08/2018] [Indexed: 11/23/2022] Open
Abstract
Background An efficient signal transduction system allows a bacterium to sense environmental cues and then to respond positively or negatively to those signals; this process is referred to as taxis. In addition to external cues, the internal metabolic state of any bacterium plays a major role in determining its ability to reside and thrive in its current environment. Similar to external signaling molecules, cytoplasmic signals are also sensed by methyl-accepting chemotaxis proteins (MCPs) via diverse ligand binding domains. Myxobacteria are complex soil-dwelling social microbes that can perform a variety of physiologic and metabolic activities ranging from gliding motility, sporulation, biofilm formation, carotenoid and secondary metabolite biosynthesis, predation, and slime secretion. To live such complex lifestyles, they have evolved efficient signal transduction systems with numerous one- and two-component regulatory system along with a large array of chemosensory systems to perceive and integrate both external and internal cues. Results Here we report the in silico characterization of a putative energy taxis cluster, Cc-5, which is present in only one amongst 34 known and sequenced myxobacterial genomes, Corallococcus coralloides. In addition, we propose that this energy taxis cluster is involved in oxygen sensing, suggesting that C. coralloides can sense (either directly or indirectly) and then respond to changing concentrations of molecular oxygen. Conclusions This hypothesis is based on the presence of a unique MCP encoded in this gene cluster that contains two different oxygen-binding sensor domains, PAS and globin. In addition, the two monooxygenases encoded in this cluster may contribute to aerobic respiration via ubiquinone biosynthesis, which is part of the cytochrome bc1 complex. Finally, we suggest that this cluster was acquired from Actinobacteria, Gammaproteobacteria or Cyanobacteria. Overall, this in silico study has identified a potentially innovative and evolved mechanism of energy taxis in only one of the myxobacteria, C. coralloides. Electronic supplementary material The online version of this article (10.1186/s12864-018-5151-6) contains supplementary material, which is available to authorized users.
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Sharma G, Burrows LL, Singer M. Diversity and Evolution of Myxobacterial Type IV Pilus Systems. Front Microbiol 2018; 9:1630. [PMID: 30072980 PMCID: PMC6060248 DOI: 10.3389/fmicb.2018.01630] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 06/29/2018] [Indexed: 12/18/2022] Open
Abstract
Type IV pili (T4P) are surface-exposed protein fibers that play key roles in the bacterial life cycle via surface attachment/adhesion, biofilm formation, motility, and development. The order Myxococcales (myxobacteria) are members of the class Deltaproteobacteria and known for their large genome size and complex social behaviors, including gliding motility, fruiting body formation, biofilm production, and prey hunting. Myxococcus xanthus, the best-characterized member of the order, relies on the appropriate expression of 17 type IVa (T4aP) genes organized in a single cluster plus additional genes (distributed throughout the genome) for social motility and development. Here, we compared T4aP genes organization within the myxobacteria to understand their evolutionary origins and diversity. We found that T4aP genes are organized as large clusters in suborder Cystobacterineae, whereas in other two suborders Sorangiineae and Nannocystineae, these genes are dispersed throughout the genome. Based on the genomic organization, the phylogeny of conserved proteins, and synteny studies among 28 myxobacterial and 66 Proteobacterial genomes, we propose an evolutionary model for the origin of myxobacterial T4aP genes independently from other orders in class Deltaproteobacteria. Considering a major role for T4P, this study further proposes the origins and evolution of social motility in myxobacteria and provides a foundation for understanding how complex-behavioral traits, such as gliding motility, multicellular development, etc., might have evolved in this diverse group of complex organisms.
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Affiliation(s)
- Gaurav Sharma
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, United States
| | - Lori L Burrows
- Department of Biochemistry and Biomedical Sciences and the Michael G. DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, ON, Canada
| | - Mitchell Singer
- Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, CA, United States
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