title: Escherichia coli PriA protein, two modes of DNA binding and activation of ATP hydrolysis.
abstract: Escherichia coli PriA protein plays crucial roles in processing of arrested replication forks. PriA serves as a sensor/stabilizer for an arrested replication fork and eventually promotes restart of DNA replication through assembly of a primosome. PriA carries a 3' terminus binding pocket required for its high affinity binding to a specific arrested fork as well as for its biological functions. We show here that PriA binds to DNA in a manner either dependent on or independent of 3' terminus recognition. The former mode of binding requires the 3' terminus binding pocket present at the N-terminal half of the 181-residue DNA binding domain and exhibits specific bipartite interaction on the template DNA. The latter mode is independent of the pocket function, but requires the C-terminal half of the same domain. ATP hydrolysis activity of PriA can be stimulated in vitro by either of the two binding modes. We propose architecture of PriA bound to various arrested replication fork structures and discuss its implication in helicase activation and ATP hydrolysis.
authors.affiliation: Genome Dynamics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 113-8613, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Tanaka
authors.forename: Toshimi
authors.initials: T
authors.lastname: Mizukoshi
authors.forename: Kaori
authors.initials: K
authors.lastname: Sasaki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kohda
authors.forename: Hisao
authors.initials: H
authors.lastname: Masai
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism*; D019915:DNA Primase / Q000378:metabolism; D004261:DNA Replication / Q000502:physiology*; D004269:DNA, Bacterial / Q000096:biosynthesis*; D004789:Enzyme Activation / Q000502:physiology; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D006868:Hydrolysis; D008958:Models, Molecular; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D000255:Adenosine Triphosphate; D019915:DNA Primase; C506743:priA protein, E coli; D004265:DNA Helicases