FtsZ collaborates with penicillin binding proteins to generate bacterial cell shape in Escherichia coli.
The mechanisms by which bacteria adopt and maintain individual shapes remain enigmatic. Outstanding questions include why cells are a certain size, length, and width; why they are uniform or irregular; and why some branch while others do not. Previously, we showed that Escherichia coli mutants lacking multiple penicillin binding proteins (PBPs) display extensive morphological diversity. Because defective sites in these cells exhibit the structural and functional characteristics of improperly localized poles, we investigated the connection between cell division and shape. Here we show that under semipermissive conditions the temperature-sensitive FtsZ84 protein produces branched and aberrant cells at a high frequency in mutants lacking PBP 5, and this phenotype is exacerbated by the loss of additional peptidoglycan endopeptidases. Surprisingly, certain ftsZ84 strains lyse at the nonpermissive temperature instead of filamenting, and inhibition of wild-type FtsZ forces some mutants into tightly wound spirillum-like morphologies. The results demonstrate that significant aspects of bacterial shape are dictated by a previously unrecognized relationship between the septation machinery and ostensibly minor peptidoglycan-modifying enzymes and that under certain circumstances improper FtsZ function can destroy the structural integrity of the cell.
Department of Microbiology and Immunology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202, USA. kyoung@medicine.nodak.edu.
Archana
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Varma
Kevin D
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Young
D001426:Bacterial Proteins / Q000378:metabolism*; D001433:Bacteriolysis; D002352:Carrier Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000166:cytology* / Q000235:genetics / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006602:Hexosyltransferases / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D002267:Muramoylpentapeptide Carboxypeptidase / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases / Q000378:metabolism*
D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C076835:FtsZ84 protein, E coli; D046915:Penicillin-Binding Proteins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase