RpoE1, an extracytoplasmic function sigma factor, is a repressor of the flagellar system in Brucella melitensis

Jonathan Ferooz, Julien Lemaire, Marie Delory, Xavier De Bolle, Jean-Jacques Letesson

Research output: Contribution to journalArticle

Abstract

The genome of Brucella melitensis contains genes coding for the sigma factors RpoD, RpoN, RpoH1, RpoH2, RpoE1 and RpoE2. Previously published data show that B. melitensis is flagellated and that an rpoE1 mutant overexpresses the flagellar protein FlgE. In this study, we demonstrate that mutation of rpoE1 causes an overexpression of the flagellar genes fliF, flgE, fliC, flaF and flbT, correlating with the production of a longer filament and thereby demonstrating that RpoE1 acts as a flagellar repressor. Moreover, mutation of rpoE1 increases the promoter activity of the flagellar master regulator ftcR, suggesting that RpoE1 acts upstream of ftcR. Together, these data show that RpoE1 represses the flagellar synthesis and filament length in B. melitensis.
Original languageEnglish
Pages (from-to)1263-8
Number of pages6
JournalMicrobiology
Volume157
Issue number5
DOIs
Publication statusPublished - 1 May 2011

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