Murein biosynthesis during a synchromous cell cycle of Escherichia coli B.

The last stages of murein biosynthesis were studied in relation to the division cycle of Escherichia coli in cells synchronized by amino acid starvation (Ron et al., J. Bacteriol. 123:374--376, 1975). Murein synthesis and the activities of the D-alanine carboxypeptidase and transpeptidase were found to vary significantly during the cell cycle. Maximal synthesis and transpeptidation were observed immediately after cell division, whereas maximal D-alanine carboxypeptidase activity was detected before cell division. These results are in agreement with our earlier findings that before cell division there is a stage of increased hydrolysis of the C-terminal D-alanine moiety of newly synthesized murein strands.