title: Hda inactivation of DnaA is the predominant mechanism preventing hyperinitiation of Escherichia coli DNA replication.
abstract: Initiation of DNA replication from the Escherichia coli chromosomal origin is highly regulated, assuring that replication occurs precisely once per cell cycle. Three mechanisms for regulation of replication initiation have been proposed: titration of free DnaA initiator protein by the datA locus, sequestration of newly replicated origins by SeqA protein and regulatory inactivation of DnaA (RIDA), in which active ATP-DnaA is converted to the inactive ADP-bound form. DNA microarray analyses showed that the level of initiation in rapidly growing cells that lack datA was indistinguishable from that in wild-type cells, and that the absence of SeqA protein caused only a modest increase in initiation, in agreement with flow-cytometry data. In contrast, cells lacking Hda overinitiated replication twofold, implicating RIDA as the predominant mechanism preventing extra initiation events in a cell cycle.
authors.affiliation: Department of Biochemistry and Molecular Biology, Georgetown University Medical Center, Washington, District of Columbia 20007, USA.
authors.forename: Johanna E
authors.initials: JE
authors.lastname: Camara
authors.forename: Adam M
authors.initials: AM
authors.lastname: Breier
authors.forename: Therese
authors.initials: T
authors.lastname: Brendler
authors.forename: Stuart
authors.initials: S
authors.lastname: Austin
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Cozzarelli
authors.forename: Elliott
authors.initials: E
authors.lastname: Crooke
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000502:physiology*; D000255:Adenosine Triphosphate / Q000737:chemistry; D000483:Alleles; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000378:metabolism*; D002453:Cell Cycle; D049109:Cell Proliferation; D004247:DNA / Q000737:chemistry; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology*; D005434:Flow Cytometry; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005838:Genotype; D015151:Immunoblotting; D008027:Light; D008957:Models, Genetic; D046912:Multiprotein Complexes; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D018741:Replication Origin; D012542:Scattering, Radiation
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; D029968:Escherichia coli Proteins; D046912:Multiprotein Complexes; D000255:Adenosine Triphosphate; D004247:DNA; D000251:Adenosine Triphosphatases; C435211:Hda protein, E coli