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Escherichia coli low‐molecular‐weight penicillin‐binding proteins help orient septal FtsZ, and their absence leads to asymmetric cell division and branching
Author(s) -
Potluri LakshmiPrasad,
de Pedro Miguel A.,
Young Kevin D.
Publication year - 2012
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/j.1365-2958.2012.08023.x
Subject(s) - ftsz , biology , cell division , escherichia coli , penicillin binding proteins , division (mathematics) , microbiology and biotechnology , branching (polymer chemistry) , cell , genetics , gene , materials science , arithmetic , mathematics , composite material
Summary Escherichia coli cells lacking low‐molecular‐weight penicillin‐binding proteins (LMW PBPs) exhibit morphological alterations that also appear when the septal protein FtsZ is mislocalized, suggesting that peptidoglycan modification and division may work together to produce cell shape. We found that in strains lacking PBP5 and other LMW PBPs, higher FtsZ concentrations increased the frequency of branched cells and incorrectly oriented Z rings by 10‐ to 15‐fold. Invagination of these rings produced improperly oriented septa, which in turn gave rise to asymmetric cell poles that eventually elongated into branches. Branches always originated from the remnants of abnormal septation events, cementing the relationship between aberrant cell division and branch formation. In the absence of PBP5, PBP6 and DacD localized to nascent septa, suggesting that these PBPs can partially substitute for the loss of PBP5. We propose that branching begins when mislocalized FtsZ triggers the insertion of inert peptidoglycan at unusual positions during cell division. Only later, after normal cell wall elongation separates the patches, do branches become visible. Thus, a relationship between the LMW PBPs and cytoplasmic FtsZ ultimately affects cell division and overall shape.