title: Exoprotein production correlates with morphotype changes of nonmotile Shewanella oneidensis mutants.
abstract: We report a previously undescribed mechanism for the rugose morphotype in Shewanella oneidensis, a research model for investigating redox transformations of environmental contaminants. Bacteria may form smooth or rugose colonies on agar plates. In general, conversion from the smooth to rugose colony morphotype is attributed to increased production of exopolysaccharide (EPS). In this work, we discovered that aflagellate S. oneidensis mutants grew into rugose colonies, whereas those with nonfunctional flagellar filaments remained smooth. EPS production was not altered in either case, but mutants with the rugose morphotype showed significantly reduced exoprotein secretion. The idea that exoproteins at a reduced level correlate with rugosity gained support from smooth suppressor strains of an aflagellate rugose fliD (encoding the capping protein) mutant, which restored the exoprotein level to the levels of the wild-type and mutant strains with a smooth morphotype. Further analyses revealed that SO1072 (a putative GlcNAc-binding protein) was one of the highly upregulated exoproteins in these suppressor strains. Most intriguingly, this study identified a compensatory mechanism of SO1072 to flagellins possibly mediated by bis-(3'-5')-cyclic dimeric GMP.
authors: Institute of Microbiology and College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
authors: Miaomiao
authors: M
authors: Shi
authors: Lin
authors: L
authors: Wu
authors: Yu
authors: Y
authors: Xia
authors: Haijiang
authors: H
authors: Chen
authors: Qixia
authors: Q
authors: Luo
authors: Linlin
authors: L
authors: Sun
authors: Haichun
authors: H
authors: Gao
mesh_terms: D000362:Agar; D001426:Bacterial Proteins / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D006152:Cyclic GMP / Q000378:metabolism; D005407:Flagella / Q000378:metabolism / Q000502:physiology*; D008124:Locomotion; D009154:Mutation; D011135:Polysaccharides, Bacterial / Q000378:metabolism; D020592:Shewanella / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D011135:Polysaccharides, Bacterial; D000362:Agar; D006152:Cyclic GMP