A mutation in the promoter region of zipA, a component of the divisome, suppresses the shape defect of RodZ-deficient cells.
RodZ is important for maintaining the rod shape of Escherichia coli. Loss of RodZ causes conversion of the rod shape to a round shape and a growth rate slower than that of wild-type cells. Suppressor mutations that simultaneously restore both the growth rates and the rod shape were isolated. Most of the suppressor mutations are found in mreB, mrdA, or mrdB. One of the mutations was in the promoter region of zipA, which encodes a crucial component of the cell division machinery. In this study, we investigated the mechanism of the suppression by this mutation. ZipA was slightly but significantly increased in the suppressor cells and led to a delay in cell division. While round-shaped mreB and mrdA mutants lose cell bipolarity, we found that round-shaped rodZ mutants retained cell bipolarity. Therefore, we concluded that a delay in the completion of septation provides extra time to elongate the cell laterally so that the zipA suppressor mutant is able to recover its ovoid or rod shape. The suppression by zipA demonstrates that the regulation of timing of septation potentially contributes to the conversion of morphology in bacterial cells.
Microbial Genetics Laboratory, Genetic Strains Research Center, National Institute of Genetics, Sokendai, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan.
Daisuke
D
Shiomi
Hironori
H
Niki
D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D002455:Cell Division; D003598:Cytoskeletal Proteins / Q000172:deficiency / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D046915:Penicillin-Binding Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D013489:Suppression, Genetic; D013997:Time Factors
D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D003598:Cytoskeletal Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D046915:Penicillin-Binding Proteins; C538795:RodZ protein, E coli; C103795:ZipA protein, E coli; C061683:mrdB protein, E coli; C078473:MreB protein, E coli; C582982:MrdA protein, E coli
Cell wall; Escherichia coli; microbial cell biology; molecular genetics