Upheaval in the bacterial nucleoid. An active chromosome segregation mechanism.
Recent advances have completely overturned the classical view of chromosome segregation in bacteria. Far from being a passive process involving gradual separation of the chromosomes, an active, possibly mitotic-like machinery is now known to exist. Soon after the initiation of DNA replication, the newly replicated copies of the oriC region, behaving rather like eukaryotic centromeres, move rapidly apart towards opposite poles of the cell. They then determine the positions that will be taken up by the newly formed sister nucleoids when DNA replication has been completed. Thus, the gradual expansion of the diffuse nucleoid camouflages an underlying active mechanism. Several genes involved in chromosome segregation in bacteria have now been defined; their possible functions are discussed.
Sharpe
M E
ME
Sir William Dunn School of Pathology, University of Oxford, UK. msharpe@molbiol.ox.ac.uk
Errington
J
J
D000705:Anaphase / Q000502:physiology*; D001412:Bacillus subtilis / Q000166:cytology / Q000235:genetics; D001419:Bacteria / Q000648:ultrastructure*; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000502:physiology; D002455:Cell Division; D002868:Chromosomal Proteins, Non-Histone; D002876:Chromosomes, Bacterial / Q000502:physiology / Q000648:ultrastructure*; D004261:DNA Replication; D004264:DNA Topoisomerases, Type I / Q000502:physiology; D004269:DNA, Bacterial / Q000096:biosynthesis; D004926:Escherichia coli / Q000166:cytology / Q000235:genetics; D029968:Escherichia coli Proteins; D008957:Models, Genetic; D015388:Organelles / Q000502:physiology* / Q000648:ultrastructure; D018741:Replication Origin; D012808:Sigma Factor; D013171:Spores, Bacterial / Q000502:physiology / Q000648:ultrastructure; D014157:Transcription Factors
D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C067035:MukB protein, E coli; C118650:SMC protein, Bacteria; D012808:Sigma Factor; D014157:Transcription Factors; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus; D004264:DNA Topoisomerases, Type I