title: A CheW homologue is required for Myxococcus xanthus fruiting body development, social gliding motility, and fibril biogenesis.
abstract: In bacteria with multiple sets of chemotaxis genes, the deletion of homologous genes or even different genes in the same operon can result in disparate phenotypes. Myxococcus xanthus is a bacterium with multiple sets of chemotaxis genes and/or homologues. It was shown previously that difA and difE, encoding homologues of the methyl-accepting chemoreceptor protein (MCP) and the CheA kinase, respectively, are required for M. xanthus social gliding (S) motility and development. Both difA and difE mutants were also defective in the biogenesis of the cell surface appendages known as extracellular matrix fibrils. In this study, we investigated the roles of the CheW homologue encoded by difC, a gene at the same locus as difA and difE. We showed that difC mutations resulted in defects in M. xanthus developmental aggregation, sporulation, and S motility. We demonstrated that difC is indispensable for wild-type cellular cohesion and fibril biogenesis but not for pilus production. We further illustrated the ectopic complementation of a difC in-frame deletion by a wild-type difC. The identical phenotypes of difA, difC, and difE mutants are consistent and supportive of the hypothesis that the Dif chemotaxis homologues constitute a chemotaxis-like signal transduction pathway that regulates M. xanthus fibril biogenesis and S motility.
authors.affiliation: Department of Biological Sciences, Auburn University, Auburn, Alabama 36849-5407, USA.
authors.forename: Kristen
authors.initials: K
authors.lastname: Bellenger
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Ma
authors.forename: Wenyuan
authors.initials: W
authors.lastname: Shi
authors.forename: Zhaomin
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000371:Agglutination; D000595:Amino Acid Sequence; D001422:Bacterial Adhesion / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002633:Chemotaxis / Q000235:genetics / Q000502:physiology*; D010861:Fimbriae, Bacterial / Q000378:metabolism; D008969:Molecular Sequence Data; D009068:Movement / Q000502:physiology; D016941:Myxococcus xanthus / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D013171:Spores, Bacterial / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; C051236:CheW protein, Bacteria