Open AccessSingle-strand binding protein enhances fidelity of DNA synthesis in vitro.
Author(s) -
Thomas A. Kunkel,
Ralph R. Meyer,
Lawrence A. Loeb
Publication year - 1979
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.76.12.6331
Subject(s) - dna polymerase , dna clamp , dna , proofreading , base pair , biology , polymerase , coding strand , polynucleotide , dna polymerase ii , microbiology and biotechnology , exonuclease , hmg box , single stranded binding protein , biochemistry , biophysics , dna binding protein , rna , gene , reverse transcriptase , transcription factor
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.