title: Replication initiation at the Escherichia coli chromosomal origin.
abstract: To initiate DNA replication, DnaA recognizes and binds to specific sequences within the Escherichia coli chromosomal origin (oriC), and then unwinds a region within oriC. Next, DnaA interacts with DnaB helicase in loading the DnaB-DnaC complex on each separated strand. Primer formation by primase (DnaG) induces the dissociation of DnaC from DnaB, which involves the hydrolysis of ATP bound to DnaC. Recent evidence indicates that DnaC acts as a checkpoint in the transition from initiation to the elongation stage of DNA replication. Freed from DnaC, DnaB helicase unwinds the parental duplex DNA while interacting the cellular replicase, DNA polymerase III holoenzyme, and primase as it intermittently forms primers that are extended by the replicase in duplicating the chromosome.
authors.affiliation: Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824-1319, USA. kaguni@msu.edu
authors.forename: Jon M
authors.initials: JM
authors.lastname: Kaguni
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002876:Chromosomes, Bacterial / Q000737:chemistry* / Q000235:genetics; D004258:DNA Polymerase III / Q000235:genetics / Q000378:metabolism*; D019915:DNA Primase / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D053488:DnaB Helicases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D011485:Protein Binding / Q000235:genetics; D018741:Replication Origin / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; C071702:DnaC protein, E coli; D029968:Escherichia coli Proteins; D019915:DNA Primase; D004258:DNA Polymerase III; C506730:dnaB protein, E coli; D053488:DnaB Helicases