Replicative DNA helicase DnaB

UniProtKB accession:  Q9X4C9

Grouped By:  Matching UniProtKB accession

UniProtKB description:  The main replicative DNA helicase, it participates in initiation and elongation during chromosome replication. Travels ahead of the DNA replisome, separating double-stranded (ds)DNA into templates for DNA synthesis. Binding of single-stranded (ss)DNA to the hexamer suggests a 2-nucleotide step size for the helicase and a hand-over-hand mechanism of DNA unwinding (Probable) (PubMed:23022319). Has ssDNA-stimulated ATPase activity (PubMed:10625492). DnaG primase stimulates the helicase activity (the helicase direction was not determine but is probably 5'-3') (PubMed:10625492, PubMed:12235389, PubMed:23022319). Loaded onto DNA by helicase loader DnaI (shown with DnaI of B.subtilis); ATP-binding enhances loading and subsequent ATP hydrolysis dissociates the complex, leaving helicase on the DNA (PubMed:17003052). Binds ssDNA and less well dsDNA, in the presence of ADPNP (probably 5'-adenylyl beta, gamma-imidodiphosphate, but not ATP) binding to both DNAs is improved (PubMed:12235389, PubMed:17003052).