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RcsCDB His‐Asp phosphorelay system negatively regulates the flhDC operon in Escherichia coli
Author(s) -
FrancezCharlot Anne,
Laugel Bruno,
Van Gemert Alice,
Dubarry Nelly,
Wiorowski Florent,
CastaniéCornet MariePierre,
Gutierrez Claude,
Cam Kaymeuang
Publication year - 2003
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2003.03601.x
Subject(s) - operon , biology , escherichia coli , response regulator , protein data bank (rcsb pdb) , l arabinose operon , caulobacter crescentus , lac operon , flagellum , gene , regulator , chemotaxis , genetics , microbiology and biotechnology , mutant , bacterial protein , biochemistry , receptor
Summary The genes involved in flagellum synthesis, motility and chemotaxis in Escherichia coli are expressed in a hierarchical fashion. At the top of the hierarchy lies the master regulator FlhDC, required for the expression of the whole set of genes. The operon flhDC is controlled by numerous regulators including H‐NS, CRP, EnvZ/OmpR, QseBC and LrhA. In the present work, we report that the flhDC operon is also negatively regulated by the His‐Asp phosphorelay system RcsCDB. The regulation is potentiated by the RcsB cofactor RcsA. Genetic analysis indicates that an RcsAB box, located downstream of the promoter, is required for the regulation. The binding of RcsB and RcsA to this site was demonstrated by gel retardation and DNase I protection assays. In addition, mutation analysis suggests that RcsA‐specific determinants lie in the right part of the ‘RcsAB box’.