Open AccessProperties of the Escherichia coli DNA Binding (Unwinding) Protein: Interaction with DNA Polymerase and DNA
Author(s) -
Ian J. Molineux,
Malcolm L. Gefter
Publication year - 1974
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.71.10.3858
Subject(s) - dna clamp , dna polymerase , dna polymerase ii , dna polymerase i , polymerase , biology , microbiology and biotechnology , dna , hmg box , dna polymerase mu , primase , biochemistry , circular bacterial chromosome , dna binding protein , gene , polymerase chain reaction , reverse transcriptase , transcription factor
TheE. coli DNA binding protein reduces the activity of the single-strand-specific nucleases associated with all three DNA polymerases known inE. coli . A slight excess of binding protein over that required to saturate the DNA template leads to total inhibition of activity of the 3′ → 5′ nucleases associated with DNA polymerases I and III, but restores maximum activity of the DNA polymerase II-associated nuclease. The binding protein forms a specific complex with DNA polymerase II in the absence of DNA, and it is this complex that degrades a DNA·binding protein complex. Binding protein also facilitates the binding of DNA polymerase II to single-stranded DNA, whereas the binding to DNA of DNA polymerase I is inhibited. These data may explain the specificity with which the binding protein enhances the synthetic ability of DNA polymerase II.