Effects of FlrBC on flagellar biosynthesis of Shewanella oneidensis. Issue 6 (14th August 2014)

• Record Type: Journal Article
• Authors: Shi, Miaomiao; Gao, Tong; Ju, Lili; Yao, Yanlai; Gao, Haichun
• Is Part Of: Molecular microbiology. Volume 93:Issue 6(2014)
• Page Start: 1269
• Page End: 1283
• Publication Date: 2014-08-14
• Subjects: Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.12731
• Languages: English
• ISSNs: 0950-382X

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>As a most conserved complex molecular machine made up of a large number of structural subunits, the flagellum is under tight regulation by hierarchical arrangements. Although variations in polar flagellar systems are found, most of them are restricted to multiple‐copy components, such as flagellins and stators. Therefore, these features are regarded to be peripheral relative to the comprehensive conservation. In this study, however, we present evidence to show that the difference in highly conserved polar flagellar systems can be surprisingly profound, even at the heart of the classical regulatory hierarchy. In Gram‐negative <italic>S</italic><italic>hewanella oneidensis</italic>, two‐component system FlrBC, whose counterpart is essential for flagellar biosynthesis and motility by directly controlling expression of class III genes in polarly flagellated bacteria such as <italic>V</italic><italic>ibrio cholerae</italic>, is dispensable for the process. The system directly controls expression of the <italic>flaA</italic> gene, encoding a flagellin of weak motility. We further show that the ratio of two flagellins, FlaA and FlaB, determines motility of a flagellum. More strikingly, overproduction of FlrC results in a peritrichously multi‐flagellated phenotype, and FlrC is likely to function as an activator in its unphosphorylated form for transcription of the <italic>flaA</italic> gene, contrasting the previously characterized counterpart.</p> </abstract>