Penicillin binding proteins: role in initiation of murein synthesis in Escherichia coli.

The consequences of the specific inhibition of penicillin binding proteins (Pbps) by beta-lactam antibiotics immediately before resumption of active growth in Escherichia coli suggest that inhibition of murein biosynthesis does not prevent the earlier steps of the initiation of cell growth in mass. The activity of Pbp 2 is apparently critical for the initiation of murein biosynthesis. Provided that Pbp 2 remains active, the other Pbps (1a, 1b, 3, 4, 5, and 6) can be inhibited without any noticeable effect on the initial rate of incorporation of new precursors into macromolecular peptidoglycan. These precursors are, in addition, inserted with a high degree of cross-linkage.