title: The Escherichia coli datA site promotes proper regulation of cell division.
abstract: In Escherichia coli inhibition of replication leads to a block of cell division. This checkpoint mechanism ensures that no cell divides without having two complete copies of the genome to pass on to the two daughter cells. The chromosomal datA site is a 1 kb region that contains binding sites for the DnaA replication initiator protein, and which contributes to the inactivation of DnaA. An excess of datA sites provided on plasmids has been found to lead to both a delay in initiation of replication and in cell division during exponential growth. Here we have investigated the effect of datA on the cell division block that occurs upon inhibition of replication initiation in a dnaC2 mutant. We found that this checkpoint mechanism was aided by the presence of datA. In cells where datA was deleted or an excess of DnaA was provided, cell division occurred in the absence of replication and anucleate cells were formed. This finding indicates that loss of datA and/or excess of DnaA protein promote cell division. This conclusion was supported by the finding that the lethality of the division-compromised mutants ftsZ84 and ftsI23 was suppressed by deletion of datA, at the lowest non-permissive temperature. We propose that the cell division block that occurs upon inhibition of DNA replication is, at least in part, due to a drop in the concentration of the ATP-DnaA protein.
authors.affiliation: College of Life Sciences, Inner Mongolia University, Da Xue Xi Lu 235, Hohhot, 010021, PR China.|Department of Cell Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo 0310, Norway.
authors.forename: Morigen
authors.initials: M
authors.lastname: Morigen
authors.affiliation: Department of Cell Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo 0310, Norway.
authors.forename: Ingvild
authors.initials: I
authors.lastname: Flåtten
authors.affiliation: Department of Cell Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo 0310, Norway.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Skarstad
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002455:Cell Division; D002876:Chromosomes, Bacterial; D004261:DNA Replication; D004269:DNA, Bacterial / Q000096:biosynthesis; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D056426:Genetic Loci; D011485:Protein Binding; D017384:Sequence Deletion
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria