RRC ID 35219
Author Uehara T, Park JT.
Title Growth of Escherichia coli: significance of peptidoglycan degradation during elongation and septation.
Journal J Bacteriol
Abstract We have found a striking difference between the modes of action of amdinocillin (mecillinam) and compound A22, both of which inhibit cell elongation. This was made possible by employment of a new method using an Escherichia coli peptidoglycan (PG)-recycling mutant, lacking ampD, to analyze PG degradation during cell elongation and septation. Using this method, we have found that A22, which is known to prevent MreB function, strongly inhibited PG synthesis during elongation. In contrast, treatment of elongating cells with amdinocillin, which inhibits penicillin-binding protein 2 (PBP2), allowed PG glycan synthesis to proceed at a nearly normal rate with concomitant rapid degradation of the new glycan strands. By treating cells with A22 to inhibit sidewall synthesis, the method could also be applied to study septum synthesis. To our surprise, over 30% of newly synthesized septal PG was degraded during septation. Thus, excess PG sufficient to form at least one additional pole was being synthesized and rapidly degraded during septation. We propose that during cell division, rapid removal of the excess PG serves to separate the new poles of the daughter cells. We have also employed this new method to demonstrate that PBP2 and RodA are required for the synthesis of glycan strands during elongation and that the periplasmic amidases that aid in cell separation are minor players, cleaving only one-sixth of the PG that is turned over by the lytic transglycosylases.
Volume 190(11)
Pages 3914-22
Published 2008-6-1
DOI 10.1128/JB.00207-08
PII JB.00207-08
PMID 18390656
PMC PMC2395050
MeSH Amdinocillin / pharmacology Amidohydrolases / metabolism Anti-Bacterial Agents / pharmacology Bacterial Proteins / genetics Bacterial Proteins / metabolism Cell Wall / metabolism Escherichia coli / drug effects Escherichia coli / growth & development* Escherichia coli Proteins / genetics Escherichia coli Proteins / metabolism Gene Expression Regulation, Bacterial Membrane Proteins / genetics Membrane Proteins / metabolism Mutation N-Acetylmuramoyl-L-alanine Amidase / genetics N-Acetylmuramoyl-L-alanine Amidase / metabolism Penicillin-Binding Proteins / genetics Penicillin-Binding Proteins / metabolism Peptidoglycan / metabolism* Periplasm / enzymology Thiourea / analogs & derivatives Thiourea / pharmacology
IF 3.006
Times Cited 56
Prokaryotes E. coli JW0106-KC(ampD)