Selection of the midcell division site in Bacillus subtilis through MinD-dependent polar localization and activation of MinC.
Bacterial cell division commences with the assembly of the tubulin-like protein, FtsZ, at midcell to form a ring. Division site selection in rod-shaped bacteria is mediated by MinC and MinD, which form a division inhibitor. Bacillus subtilis DivIVA protein ensures that MinCD specifically inhibits division close to the cell poles, while allowing division at midcell. We have examined the localization of MinC protein and show that it is targeted to midcell and retained at the mature cell poles. This localization is reminiscent of the pattern previously described for MinD. Localization of MinC requires both early (FtsZ) and late (PbpB) division proteins, and it is completely dependent on MinD. The effects of a divIVA mutation on localization of MinC now suggest that the main role of DivIVA is to retain MinCD at the cell poles after division, rather than recruitment to nascent division sites. By overexpressing minC or minD, we show that both proteins are required to block division, but that only MinD needs to be in excess of wild-type levels. The results suggest a mechanism whereby MinD is required both to pilot MinC to the cell poles and to constitute a functional division inhibitor.
Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
A L
AL
Marston
J
J
Errington
D000251:Adenosine Triphosphatases / Q000502:physiology*; D001412:Bacillus subtilis / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D001426:Bacterial Proteins / Q000502:physiology*; D002352:Carrier Proteins; D018797:Cell Cycle Proteins / Q000502:physiology*; D002455:Cell Division / Q000502:physiology; D016764:Cell Polarity; D003598:Cytoskeletal Proteins; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase; D046915:Penicillin-Binding Proteins; D046928:Peptidoglycan Glycosyltransferase; D010458:Peptidyl Transferases; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013045:Species Specificity
D001426:Bacterial Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; C104636:DivIVA protein, bacteria; D029968:Escherichia coli Proteins; C478704:FtsI protein, E coli; C071525:FtsZ protein, Bacteria; C080466:MinC protein, Bacteria; D046915:Penicillin-Binding Proteins; D011993:Recombinant Fusion Proteins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D046928:Peptidoglycan Glycosyltransferase; D002267:Muramoylpentapeptide Carboxypeptidase; D000251:Adenosine Triphosphatases; C072069:MinD protein, E coli