title: Single-strand binding protein enhances fidelity of DNA synthesis in vitro.
abstract: The effect of Escherichia coli single-strand binding protein on the accuracy of in vitro DNA synthesis has been determined by using two independent methods. By using the synthetic polynucleotide poly[d(A-T)] and measuring dGTP misincorporation or by using phi X174 DNA and measuring nucleotide substitutions, we found that binding protein increases the fidelity of DNA synthesis by as much as 10-fold. This increase is observed with DNA polymerases of divergent sources and is progressive with increasing concentration of binding protein. The increased accuracy observed with DNA polymerases lacking a 3' leads to 5' exonuclease points to a mechanism other than augmented proofreading. In accord with the properties of single-strand binding proteins, it is suggested that increased fidelity is a result of enhanced base selection by the DNA polymerase, resulting from increased rigidity of the template due to its interaction with binding protein.
mesh_terms: D001483:Base Sequence; D004265:DNA Helicases / Q000378:metabolism*; D004258:DNA Polymerase III / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D009690:Nucleic Acid Conformation; D013379:Substrate Specificity; D013698:Templates, Genetic
chemical_list: D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase; D004265:DNA Helicases