Flagellin gene (fliC) of Thermus thermophilus HB8: characterization of its product and involvement to flagella assembly and microbial motility

Abstract

Thermus thermophilus HB8 flagellin protein (FliC) is encoded by the TTHC004 (fliC) gene, which is located in the pTT8 plasmid of the bacterium. Flagellin monomer and flagella fibres were isolated from a culture of T. thermophilus grown in rich medium, or in mineral salt medium with sodium gluconate as the carbon source. Western blot immunodetection with anti-FliC revealed a stable complex (FliC)(1)(FliS)(2) of flagellin (FliC, 27.7 kDa) with a homodimer of FliS (FliS, 18.2 kDa) that are encoded by TTHC004 and TTHC003 genes, respectively. The complex is dissociable at low pHs and/or by heat treatment. Glycan staining of purified flagella and treatment with N-glycosidase F suggested that flagellin of T. thermophilus is a glycosylated protein. Size exclusion chromatography revealed that flagellar filaments (FliC) have a molecular mass higher than 200 kDa. The formation of flagella is enhanced after prolonged cultivation time where phosphate and other nutrient were depleted, giving in the bacterium considerable swimming motility in low viscosity media.

FliW and FliS Function Independently To Control Cytoplasmic Flagellin Levels in Bacillus subtilis

“…Another model suggests that FliS could maintain Hag in an unfolded, export-competent state prior to secretion (12). In B. subtilis, however, FliW functionally binds to Hag in the cytoplasm, suggesting that perhaps sufficient folding occurs at least at the interaction site, and other work suggests that FliS binding does not inhibit Hag folding in vitro (13,14). Finally, FliS could catalyze the interaction of Hag with the secretion apparatus and thereby enhance the rate of export.…”

“…FliS binds to the disordered C terminus of flagellin subunits in the cytoplasm, and the FliS-flagellin interaction has been reported to have a number of biological consequences (12)(13)(14). FliS has been shown to protect flagellin monomers from intracellular proteolysis in vivo and inhibits the polymerization of flagellin in vitro (12,13).…”

An iTRAQ-Based Comparative Proteomics Analysis of the Biofilm and Planktonic States of Aeromonas veronii TH0426

“…Flagellin, an important component of flagellum, was one of 147 downregulated proteins. Moreover, bacterial flagella are the movement organs but are also important virulence factors [40], and flagellar filaments are encoded by the fla gene in A. veronii TH0426 [1]. While in a Salmonella enteritidis study, the fliC gene encoded them, and the study showed the formation ability of fliC gene deletion strain was poorer than that of the wild strain [41], that indicated fliC gene plays an important role in the formation of biofilm [42].…”

Characterization of the phosphate-specific transport system inCronobacter sakazakiiBAA-894

“…For example, carbon limitation induced chemotaxis and motility of B. subtilis (Papaneophytou et al . ), and phosphate limitation enhanced exopolysaccharide biosynthesis in Rhizobium melioti SU47 (Zhan et al . ).…”

“…These signals affect the physiological and morphological changes through the transcriptional regulatory systems to enable organisms to adapt the environment effectively for survival. For example, carbon limitation induced chemotaxis and motility of B. subtilis (Papaneophytou et al 2012), and phosphate limitation enhanced exopolysaccharide biosynthesis in Rhizobium melioti SU47 (Zhan et al 1991). In E. coli, there is a Pho regulon which contains dozens of genes and responses to P i availability in the environment.…”