Volume growth, murein synthesis, and murein cross-linkage during the division cycle of Escherichia coli PA3092

Publisher Website
Google Scholar
Abstract
Cells of E. coli PA3092 were synchronized by centrifugal elutriation. The synchronously growing cells were double labeled with 3H or DL-[meso-2,6-14C]diaminopimelic acid (DAP) at different times. Cells incorporated [3H]DAP at a continuously increasing rate during their cycle, with a maximum occurring at about 30 min before division for trichloroacetic acid-precipitated cells (whole cells) and about 10 min before division for sodium dodecyl sulfate-treated cells (sacculi). This was in good agreement with the observed kinetics of volume growth under these conditions. Furazlocillin, which preferentially interacts with penicillin-binding protein 3, modified the pattern of incorporation of [3H]DAP. EM indicated that furazlocillin did not inhibit the initiation of division but rather its completion. The cross-linking of the murein inserted at different times during synchronous growth was also measured. The highest percentages occurred around division. At this same time, the cross-linking of old peptidoglycan was decreased.