Turnover and recycling of the murein sacculus in oligopeptide permease-negative strains of Escherichia coli: indirect evidence for an alternative permease system and for a monolayered sacculus.
Turnover of murein in oligopeptide permease-negative Escherichia coli cells appeared to be minimal or nonexistent. In one strain in which it was possible to measure turnover during the first generation of chase, it was found that the rate of turnover was constant throughout a chase of three generations. This result suggests that an "inside-to-outside" mode of growth of the sacculus does not occur in E. coli. Turnover, though minimal, was significantly higher from cells labeled uniformly than from cells labeled only in the lateral wall, suggesting that a significant portion of the observed turnover is related to cell separation. Actually, turnover only appeared to be minimal in opp mutant strains. Tripeptides were being released by turnover at a rate of about 50% per generation and then were efficiently recycled. This suggests that in addition to opp, a low-affinity uptake system for tripeptide derived from the sacculus may exist.
Park
J T
JT
Department of Molecular Biology and Microbiology, Tufts University, Boston, Massachusetts 02111.
D002455:Cell Division; D002473:Cell Wall / Q000378:metabolism*; D003960:Diaminopimelic Acid / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics*; D010455:Peptides / Q000378:metabolism; D010457:Peptidoglycan / Q000378:metabolism*; D014538:Uridine Diphosphate N-Acetylmuramic Acid / Q000031:analogs & derivatives / Q000378:metabolism
D026901:Membrane Transport Proteins; D010455:Peptides; D010457:Peptidoglycan; D014538:Uridine Diphosphate N-Acetylmuramic Acid; D003960:Diaminopimelic Acid