title: Mutational analysis of genes involved in pilus structure, motility and transformation competency in the unicellular motile cyanobacterium Synechocystis sp. PCC 6803.
abstract: The relevance of pilus-related genes to motility, pilus structure on the cell surface and competency of natural transformation was studied by gene disruption analysis in the unicellular motile cyanobacterium Synechocystis: sp. PCC 6803. The genes disrupted in this study were chosen as related to the pil genes for biogenesis of the type IV pili in a Gram-negative bacterium Pseudomonas aeruginosa. It was found that motility of Synechocystis cells was lost in the mutants of slr0063, slr1274, slr1275, slr1276, slr1277 and sll1694 together with a simultaneous loss of the thick pili on the cell surface. Competency of the natural transformation was lost in the mutants listed above and slr0197-disruptant. The gene slr0197 was previously predicted as a competence gene by a search with sequence-independent DNA-binding structure [Yura et al. (1999) DNA Res. 6: 75]. It was suggested that both DNA uptake for natural transformation and motility are mediated by a specific type IV-like pilus structure, while a putative DNA-binding protein encoded by slr0197 is additionally required for the DNA uptake. Based on the homology with the pil genes in P: aeruginosa, slr0063, slr1274, slr1275, slr1276, slr1277 and sll1694 were designated pilB1, pilM, pilN, pilO, pilQ and pilA1, respectively. The gene slr0197 was designated comA.
authors.affiliation: Department of Life Sciences (Biology), University of Tokyo, Komaba 3-8-1, Meguro, Tokyo, 153-8902 Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yoshihara
authors.forename: X
authors.initials: X
authors.lastname: Geng
authors.forename: S
authors.initials: S
authors.lastname: Okamoto
authors.forename: K
authors.initials: K
authors.lastname: Yura
authors.forename: T
authors.initials: T
authors.lastname: Murata
authors.forename: M
authors.initials: M
authors.lastname: Go
authors.forename: M
authors.initials: M
authors.lastname: Ohmori
authors.forename: M
authors.initials: M
authors.lastname: Ikeuchi
mesh_terms: D000595:Amino Acid Sequence; D002478:Cells, Cultured; D000458:Cyanobacteria / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D004252:DNA Mutational Analysis; D010861:Fimbriae, Bacterial / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D005798:Genes, Bacterial; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D009154:Mutation; D014157:Transcription Factors; D014170:Transformation, Genetic
chemical_list: D014157:Transcription Factors