Cell cycle parameters of XXXX : interdependence of the biosynthetic cell cycle and the interdivision cycle.

@entity3954 @entity3208 @entity9700 @entity5609 @entity969 @entity802 @entity1014 @entity7265 @entity526
We investigated the time periods of DNA replication, lateral cell wall extension, and septum formation within the cell cycle of @entity5609 . Cells were cultivated under three different conditions, yielding interdivision times of approximately 55, 57, and 160 min, respectively. Synchrony was achieved by @entity969 density gradient centrifugation. The time periods were estimated by division inhibition studies with @entity7265 , mecillinam, and @entity802 . In addition, DNA replication was measured by @entity1014 incorporation, and murein biosynthesis was measured by incorporation of @entity3954 into @entity3208 -insoluble murein sacculi. At interdivision times of 55 to 57 min murein biosynthesis for reproduction of a unit cell lasted longer than the interdivision time itself, whereas DNA replication finished within 40 min. Surprisingly, inhibition of DNA replication by @entity802 did not inhibit the subsequent cell division but rather the one after that. Because @entity9700 fails to express several reactions of the recA-dependent SOS functions known from @entity526 , the drug allowed us to determine which DNA replication period actually governed which cell division. Taken together, the results indicate that at an interdivision time of 55 to 57 min, the biosynthetic cell cycle of @entity9700 lasts approximately 120 min. To achieve the observed interdivision time, it is necessary that two subsequent biosynthetic cell cycles be tightly interlocked. The implications of these findings for the regulation of the cell cycle are discussed.
