Themes and variations in prokaryotic cell division

Perhaps the biggest single task facing a bacterial cell is to divide into d aughter cells that contain the normal complement of chromosomes. Recent tec hnical and conceptual breakthroughs in bacterial cell biology, combined wit h the flood of genome sequence information and the excellent genetic tools in sec cl al model systems, have shed new light on the mechanism of prokary otic cell division. There is good evidence that in most species, a molecula r machine, organized by the tubulin-like FtsZ protein, assembles at the sit e of division and orchestrates the splitting of the cell. The determinants that target the machine to the right place at the right time are beginning to be understood in the model systems, but it is still a mystery how the ma chine actually generates the constrictive force necessary for cytokinesis. Moreover, although some cell division determinants such as FtsZ are present in a broad spectrum of prokaryotic species, the lack of FtsZ in some speci es and different profiles of cell division proteins in different families s uggests that there are diverse mechanisms for regulating cell division. (C) 2000 Federation of European Microbiological Societies. Published by Elsevi er Science B.V. All rights reserved.