Flagellar biosynthesis protein FlhA ..

The two functions of EpsE are mechanistically separable as indicated by the phenotype of mutations in the EpsE ribosome binding site (RBS) (). The RBS mutants reduced the level of EpsE protein below the limit of detection, but nonetheless retained the ability to produce EPS and form colonies with complex architecture (, ). We infer the mechanism of EPS biosynthesis is independent of protein levels and therefore EpsE acts sub-stoichiometrically like an enzyme. The RBS mutants and other mutations that reduced EpsE protein levels, however, resulted in a loss of motility inhibition. We infer that the mechanism of clutch function is dependent on protein levels and therefore EpsE acts stoichiometrically, via a protein-protein interaction. EpsE is thought to interact directly with FliG, and for each basal body, approximately 26 FliG subunits polymerize into a wheel-like rotor –. The number of EpsE molecules that must interact with the rotor to inhibit rotation of a flagellum is finite but unknown.

(2012) Swarming motility and the control of master regulators of flagellar biosynthesis, Mol.

N2 - BvgAS is a two-component system of Bordetella pertussis involved in the reciprocal regulation of the virulence genes and the flagellar biosynthesis. In this study, we found that expression of bvgAS in Escherichia coli also results in reduced motility. The repression was relieved by the addition of known chemical modulators of BvgAS such as MgSO4 and nicotinic acid, indicating that functional BvgAS proteins are required for the negative control of E. coli motility. In addition, BvgAS repressed the transcription of the flhDC master operon of E. coli, which consequently caused non- flagellation on the cell surface. However, expression of BvgAS had no effect on stress-resistant motile mutants of E. coli. These data suggest that E. coli may have BvgA-like protein(s) involved in the regulatory interactions between the stress response and the flagellar biosynthesis.


flhA flagellar biosynthesis protein FlhA []

AB - BvgAS is a two-component system of Bordetella pertussis involved in the reciprocal regulation of the virulence genes and the flagellar biosynthesis. In this study, we found that expression of bvgAS in Escherichia coli also results in reduced motility. The repression was relieved by the addition of known chemical modulators of BvgAS such as MgSO4 and nicotinic acid, indicating that functional BvgAS proteins are required for the negative control of E. coli motility. In addition, BvgAS repressed the transcription of the flhDC master operon of E. coli, which consequently caused non- flagellation on the cell surface. However, expression of BvgAS had no effect on stress-resistant motile mutants of E. coli. These data suggest that E. coli may have BvgA-like protein(s) involved in the regulatory interactions between the stress response and the flagellar biosynthesis.


WikiGenes - fliP - flagellar biosynthesis protein

(1999) Multiple control of flagellum biosynthesis in Escherichia coli: role of H-NS protein and the cyclic AMP-catabolite activator protein complex in transcription of the flhDC master operon, J.

which are essential in flagella biosynthesis.

Many bacteria inhibit motility concomitant with the synthesis of an extracellular polysaccharide matrix and the formation of biofilm aggregates. In Bacillus subtilis biofilms, motility is inhibited by EpsE, which acts as a clutch on the flagella rotor to inhibit motility, and which is encoded within the 15 gene eps operon required for EPS production. EpsE shows sequence similarity to the glycosyltransferase family of enzymes, and we demonstrate that the conserved active site motif is required for EPS biosynthesis. We also screen for residues specifically required for either clutch or enzymatic activity and demonstrate that the two functions are genetically separable. Finally, we show that, whereas EPS synthesis activity is dominant for biofilm formation, both functions of EpsE synergize to stabilize cell aggregates and relieve selective pressure to abolish motility by genetic mutation. Thus, the transition from motility to biofilm formation may be governed by a single bifunctional enzyme.