Author:
Gmeiner J,Sarnow E,Milde K
Abstract
We investigated the time periods of DNA replication, lateral cell wall extension, and septum formation within the cell cycle of Proteus mirabilis. Cells were cultivated under three different conditions, yielding interdivision times of approximately 55, 57, and 160 min, respectively. Synchrony was achieved by sucrose density gradient centrifugation. The time periods were estimated by division inhibition studies with cephalexin, mecillinam, and nalidixic acid. In addition, DNA replication was measured by thymidine incorporation, and murein biosynthesis was measured by incorporation of N-acetylglucosamine into sodium dodecyl sulfate-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 nalidixic acid did not inhibit the subsequent cell division but rather the one after that. Because P. mirabilis fails to express several reactions of the recA-dependent SOS functions known from Escherichia coli, 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 P. mirabilis 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.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference22 articles.
1. Model for the structure of the shape-maintaining layer of the Escherichia coli cell envelope;Braun V.;J. Bacteriol.,1973
2. Two pathways of division inhibition in UV-irradiated E. coli;Burton B.;Mol. Gen. Genet.,1983
3. Chromosome replication and the division cycle of Escherichia coli B;Cooper S.;J. Mol. Biol.,1968
4. Daneo-Moore L. and G. D. Shockman. 1977. The bacterial cell surface in growth and division p. 597-715. In G. Poste and G. L. Nicolson (ed.) The synthesis assembly and turnover of cell surface components. Elsevier Biomedical Press Amsterdam.
5. Donachie W. D. 1979. The cell cycle of Escherichia coli p. 11-35. In J. H. Parish (ed.) Developmental biology of prokaryotes. Blackwell Scientific Publications Ltd. Oxford.
Cited by
7 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献