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Nature Reviews. Microbiology Oct 2003The myxobacteria are Gram-negative organisms that are capable of multicellular, social behaviour. In the presence of nutrients, swarms of myxobacteria feed cooperatively... (Review)
Review
The myxobacteria are Gram-negative organisms that are capable of multicellular, social behaviour. In the presence of nutrients, swarms of myxobacteria feed cooperatively by sharing extracellular digestive enzymes, and can prey on other bacteria. When the food supply runs low, they initiate a complex developmental programme that culminates in the production of a fruiting body. Myxobacteria move by gliding and have two, polarly positioned engines to control their motility. The two engines undergo coordinated reversals, and changes in the reversal frequency and speed are responsible for the different patterns of movement that are seen during development. The myxobacteria communicate with each other and coordinate their movements through a cell-contact-dependent signal. Here, the cell movements that culminate in the development of the multicellular fruiting body are reviewed.
Topics: Morphogenesis; Myxococcales; Myxococcus xanthus; Signal Transduction; Spores, Bacterial
PubMed: 15040179
DOI: 10.1038/nrmicro733 -
Journal of Bacteriology Feb 2018Chemosensory systems (CSS) are among the most complex organizations of proteins functioning cooperatively to regulate bacterial motility and other cellular activities.... (Comparative Study)
Comparative Study
Chemosensory systems (CSS) are among the most complex organizations of proteins functioning cooperatively to regulate bacterial motility and other cellular activities. These systems have been studied extensively in bacteria, and usually, they are present as a single system. Eight CSS, the highest number in bacteria, have been reported in DK1622 and are involved in coordinating diverse functions. Here, we have explored and compared the CSS in all available genomes of order members contain 97 to 476 two-component system (TCS) proteins, which assist the bacteria in surviving and adapting to varying environmental conditions. The number of myxobacterial CSS ranges between 1 and 12, with the largest number in family and the smallest in CheA protein was used as a phylogenetic marker to infer evolutionary relatedness between different CSS, and six novel CSS ("extra CSS" [ECSS]) were thus identified in the myxobacteria besides the previously reported Che1 to Che8 systems from Che1 to Che8 systems are monophyletic to deltaproteobacteria, whereas the newly identified ECSS form separate clades with different bacterial classes. The comparative modular organization was concordant with the phylogeny. Four clusters lacking CheA proteins were also identified via CheB-based phylogenetic analysis and were categorized as accessory CSS (ACSS). In , an orphan CSS was identified, in which both CheA and CheB were absent. The novel, accessory, and orphan multimodular CSS identified here suggest the emergence of myxobacterial CSS and could assist in further characterizing their roles. This study is focused on chemosensory systems (CSS), which help the bacterium in directing its movement toward or away from chemical gradients. CSS are present as a single system in most of the bacteria except in some groups, including , which has 8 CSS, the highest number reported to date. This is the first comprehensive study carrying out a comparative analysis of the 22 available myxobacterial genomes, which suggests the evolutionary diversity of these systems. We are interested in understanding the distribution of CSS within all known myxobacteria and their probable evolution.
Topics: Bacterial Physiological Phenomena; Bacterial Proteins; Evolution, Molecular; Genome, Bacterial; Genomics; Myxococcales; Phylogeny; Protein Kinases; Signal Transduction
PubMed: 29158239
DOI: 10.1128/JB.00620-17 -
Molecular Microbiology Jan 2014Through cooperative interactions, bacteria can build multicellular communities. To ensure that productive interactions occur, bacteria must recognize their neighbours... (Review)
Review
Through cooperative interactions, bacteria can build multicellular communities. To ensure that productive interactions occur, bacteria must recognize their neighbours and respond accordingly. Molecular recognition between cells is thus a fundamental behaviour, and in bacteria important discoveries have been made. This MicroReview focuses on a recently described recognition system in myxobacteria that is governed by a polymorphic cell surface receptor called TraA. TraA regulates outer membrane exchange (OME), whereby myxobacterial cells transiently fuse their OMs to efficiently transfer proteins and lipids between cells. Unlike other transport systems, OME is rather indiscriminate in what OM goods are transferred. In contrast, the recognition of partnering cells is discriminatory and only occurs between cells that bear identical or closely related TraA proteins. Therefore TraA functions in kin recognition and, in turn, OME helps regulate social interactions between myxobacteria. Here, I discuss and speculate on the social and evolutionary implications of OME and suggest it helps to guide their transition from free-living cells into coherent and functional populations.
Topics: Bacterial Outer Membrane Proteins; Bacterial Proteins; Biological Evolution; Lipids; Microbial Interactions; Myxococcales; Protein Transport
PubMed: 24261719
DOI: 10.1111/mmi.12450 -
MBio Apr 2020The microcin C (McC) and related compounds are potent Trojan horse peptide-nucleotide antibiotics. The peptide part facilitates transport into sensitive cells. Inside...
The microcin C (McC) and related compounds are potent Trojan horse peptide-nucleotide antibiotics. The peptide part facilitates transport into sensitive cells. Inside the cell, the peptide part is degraded by nonspecific peptidases releasing an aspartamide-adenylate containing a phosphoramide bond. This nonhydrolyzable compound inhibits aspartyl-tRNA synthetase. In addition to the efficient export of McC outside the producing cells, special mechanisms have evolved to avoid self-toxicity caused by the degradation of the peptide part inside the producers. Here, we report that histidine-triad (HIT) hydrolases encoded in biosynthetic clusters of some McC homologs or by standalone genes confer resistance to McC-like compounds by hydrolyzing the phosphoramide bond in toxic aspartamide-adenosine, rendering them inactive. Uncovering the mechanisms of resistance is a required step for countering the looming antibiotic resistance crisis. In this communication, we show how universally conserved histidine-triad hydrolases provide resistance to microcin C, a potent inhibitor of bacterial protein synthesis.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Bacteriocins; Biosynthetic Pathways; Drug Resistance, Bacterial; Escherichia coli; Hydrolases; Multigene Family; Myxococcales; Operon; Peptides
PubMed: 32265328
DOI: 10.1128/mBio.00497-20 -
Actinobacteria and Myxobacteria-Two of the Most Important Bacterial Resources for Novel Antibiotics.Current Topics in Microbiology and... 2016Bacteria have been by far the most promising resource for antibiotics in the past decades and will in all undoubtedly remain an important resource of innovative... (Review)
Review
Bacteria have been by far the most promising resource for antibiotics in the past decades and will in all undoubtedly remain an important resource of innovative bioactive natural products in the future. Actinobacteria have been screened for many years, whereas the Myxobacteria have been underestimated in the past. Even though Actinobacteria belong to the Gram-positive and Myxobacteria to the Gram-negative bacteria both groups have a number of similar characters, as they both have huge genomes with in some cases more than 10kB and a high GC content and they both can differentiate and have often cell cycles including the formation of spores. Actinobacteria have been used for the antibiotic research for many years, hence it is often discussed whether this resource has now been exhaustively exploited but most of the screening programs from pharmaceutical companies were basing on the cultivation mainly of members of the genus Streptomyces or Streptomyces like strains (e.g., some Saccharopolyspora, Amycolatopsis or Actinomadura species) by use of standard methods so that many of the so called "neglected" Actinobacteria were overlooked the whole time. The present review gives an overview on the state of the art regarding new bioactive compounds with a focus on the marine habitats. Furthermore, the evaluation of Myxobacteria in our ongoing search for novel anti-infectives is highlighted.
Topics: Actinobacteria; Anti-Bacterial Agents; Myxococcales
PubMed: 27704272
DOI: 10.1007/82_2016_503 -
Journal of Molecular Microbiology and... 2004Gliding motility is defined as translocation in the direction of the long axis of the bacterium while in contact with a surface. This definition leaves unspecified any... (Review)
Review
Gliding motility is defined as translocation in the direction of the long axis of the bacterium while in contact with a surface. This definition leaves unspecified any mechanism and, indeed, it appears that there is more than one physiological system underlying the same type of motion. Currently, two distinct mechanisms have been discovered in myxobacteria. One requires the extension, attachment, and retraction of type IV pili to pull the cell forwards. Recent experimental evidence suggests that a second mechanism for gliding motility involves the extrusion of slime from an organelle called the 'junctional pore complex'. This review discusses the role of slime extrusion and the junctional pore complex in the gliding motility of both cyanobacteria and myxobacteria.
Topics: Cyanobacteria; Microscopy, Electron; Movement; Myxococcales
PubMed: 15170405
DOI: 10.1159/000077871 -
FEMS Microbiology Reviews Oct 2000This review presents an overview of the present status of the biology of the myxobacteria, including the molecular biology of the systems that control and regulate... (Review)
Review
This review presents an overview of the present status of the biology of the myxobacteria, including the molecular biology of the systems that control and regulate myxobacterial gliding movement and morphogenesis. The present status of myxobacterial taxonomy and phylogeny is described. The evolutionary biology of the myxobacteria is emphasized with respect to their social behavior and the molecular basis of their signal chains. Most important within the metabolic physiology are the biologically active secondary metabolites of myxobacteria and their molecular mechanisms of action. The global distribution of myxobacteria in soils is described on the basis of data given in the literature as well as of comprehensive analyses of 1398 soil samples from 64 countries of all continents. The results are analyzed with respect to the spectrum and number of species depending on ecological and habitat-specific factors. The myxobacterial floras of different climate zones are compared. Included are myxobacterial species adapted to extreme biotopes. The efficiency of different methods used presently for isolation of myxobacteria is compared.
Topics: Antarctic Regions; Anti-Bacterial Agents; Bryopsida; Classification; Climate; Genome, Bacterial; Hydrogen-Ion Concentration; Myxococcales; Phylogeny; Soil Microbiology
PubMed: 10978544
DOI: 10.1111/j.1574-6976.2000.tb00548.x -
FEBS Letters Jun 2011The exploitation of cytochromes P450 for novel biotechnological application and for the investigation of their physiological function is of great scientific interest in... (Review)
Review
The exploitation of cytochromes P450 for novel biotechnological application and for the investigation of their physiological function is of great scientific interest in this post genomic era, where an extraordinary biodiversity of P450 genes has been derived from all forms of life. The study of P450s in the myxobacterium Sorangium cellulosum strain So ce56, the producer of novel secondary metabolites of pharmaceutical interest is the research topic, in which we were engaged since the beginning of its genome sequencing project. We herein disclosed the cytochrome P450 complements (CYPomes) of spore-forming myxobacterial species, Stigmatella aurantiaca DW4/3-1, Haliangium ochraceum DSM 14365 and Myxococcus xanthus DK1622, and their potential pharmaceutical significance has been discussed.
Topics: Cytochrome P-450 Enzyme System; Genome, Bacterial; Genomics; Myxococcales; Spores, Bacterial
PubMed: 21521637
DOI: 10.1016/j.febslet.2011.04.035 -
Natural Product Reports Dec 2007Over the last 20 years myxobacteria have made their way from highly exotic organisms to one of the major sources of microbial natural products with interesting... (Review)
Review
Over the last 20 years myxobacteria have made their way from highly exotic organisms to one of the major sources of microbial natural products with interesting biological activities. Recent progress towards achieving a better understanding of the genetics and the biochemistry of myxobacterial secondary metabolism, revealed the involvement of numerous exceptional combinations of polyketide synthases and nonribosomal peptide synthetases operating far from textbook biosynthetic logic. In this Highlight, selected examples of recently described systems are discussed in comparison to all myxobacterial natural product assembly lines known to date.
Topics: Biochemical Phenomena; Biochemistry; Biological Products; Models, Biological; Molecular Structure; Myxococcales; Peptide Synthases; Polyketide Synthases
PubMed: 18033576
DOI: 10.1039/b706416k -
Microbiology Spectrum Sep 2021Bacteria are globally distributed in various environments on earth, but a global view of the geographic diversity and distribution of a single taxon is lacking. The...
Bacteria are globally distributed in various environments on earth, but a global view of the geographic diversity and distribution of a single taxon is lacking. The Earth Microbiome Project (EMP) has established a global collection of microbial communities, providing the possibility for such a survey. is a bacterial order with a potent ability to produce diverse natural products and have wide application potential in agriculture, biomedicine, and environmental protection. In this study, through a comparative analysis of the EMP data and public information, we determined that myxobacteria account for 2.34% of the total bacterial operational taxonomic units (OTUs), and are one of the most diverse bacterial groups on Earth. OTUs are globally distributed and prefer nonsaline soil and sediments, followed by saline environments, but rarely appear in host-associated environments. Myxobacteria are among the least-investigated bacterial groups. The presently cultured and genome-sequenced myxobacteria are most likely environmentally widespread and abundant taxa, and account for approximately 10% and 7% of the myxobacterial community (>97% similarity), respectively. This global panoramic view of the geographic distribution and diversity of myxobacteria, as well as their cultured and genome-sequenced information, will enable us to explore these important bioresources more reasonably and efficiently. The diversity and distribution of myxobacteria beyond the EMP data are further discussed. The diversity and distribution of bacteria are crucial for our understanding of their ecological importance and application potential. Myxobacteria are fascinating prokaryotes with multicellular behaviors and a potent capacity for producing secondary metabolites, and have a wide range of potential applications. The ecological importance of myxobacteria in major ecosystems is becoming established, but the global geographic diversity and distribution remain unclear. From a global survey we revealed that OTUs are globally distributed and prefer nonsaline soil and sediments, followed by saline environments, but rarely appear in host-associated environments. The global panoramic view of the geographic distribution and diversity of myxobacteria, as well as their cultured and genome-sequenced information, will enable us to explore these important bioresources more reasonably and efficiently.
Topics: Biodiversity; Environmental Microbiology; Myxococcales; Phylogeny; Soil; Soil Microbiology
PubMed: 34259548
DOI: 10.1128/Spectrum.00012-21