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The role of FlhF and HubP as polar landmark proteins in S hewanella putrefaciens CN ‐32
Author(s) -
Rossmann Florian,
Brenzinger Susanne,
Knauer Carina,
Dörrich Anja K.,
Bubendorfer Sebastian,
Ruppert Ulrike,
Bange Gert,
Thormann Kai M.
Publication year - 2015
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 - 10.1111/mmi.13152
Subject(s) - periplasmic space , chemotaxis , biology , microbiology and biotechnology , flagellum , transmembrane protein , cell polarity , transport protein , bacteria , biochemistry , cell , escherichia coli , genetics , receptor , gene
Summary Spatiotemporal regulation of cell polarity plays a role in many fundamental processes in bacteria and often relies on ‘landmark’ proteins which recruit the corresponding clients to their designated position. Here, we explored the localization of two multi‐protein complexes, the polar flagellar motor and the chemotaxis array, in S hewanella putrefaciens CN ‐32. We demonstrate that polar positioning of the flagellar system, but not of the chemotaxis system, depends on the GTPase FlhF . In contrast, the chemotaxis array is recruited by a transmembrane protein which we identified as the functional ortholog of V ibrio cholerae HubP . Mediated by its periplasmic N ‐terminal LysM domain, Sp HubP exhibits an FlhF ‐independent localization pattern during cell cycle similar to its Vibrio counterpart and also has a role in proper chromosome segregation. In addition, while not affecting flagellar positioning, Sp HubP is crucial for normal flagellar function and is involved in type IV pili‐mediated twitching motility. We hypothesize that a group of HubP / FimV homologs, characterized by a rather conserved N ‐terminal periplasmic section required for polar targeting and a highly variable acidic cytoplasmic part, primarily mediating recruitment of client proteins, serves as polar markers in various bacterial species with respect to different cellular functions.