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.

AUTOR(ES)

Park, J T

RESUMO

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.

Documentos Relacionados

• Evidence for diffuse growth of the cylindrical portion of the Escherichia coli murein sacculus.
• Interactions of Escherichia coli membrane lipoproteins with the murein sacculus.
• Molecular model for elongation of the murein sacculus of Escherichia coli.
• Regulation of peptide transport in Escherichia coli: induction of the trp-linked operon encoding the oligopeptide permease.
• Recycling of murein by Escherichia coli.