title: On the fidelity of DNA polymerase alpha: the influence of alpha-thio dNTPs, Mn2+ and mismatch repair.
abstract: The phi X174am16 revertant system has been used to investigate the influence of alpha-thio-dNTPs and of Mn2+ on the fidelity of the 9S DNA polymerase alpha from calf thymus. Upon substituting dGTP by alpha-thio-dGTP during the in vitro replication, a nearly tenfold decrease in the frequency of G:G and G:T mispairs is observed. The formation of all other mispairs is not changed in the presence of the corresponding alpha-thio-dNTP. Mn2+ at concentrations of 0.5 mM does not influence the frequencies of the mispairs. The expression rate of errors formed during in vitro replication in the (-) strand has been determined for all mispairs detectable in the phi Xam16 system. The (-) strand expression of G:T, T:T and C:T mismatches is about 50%, whereas for A:G, G:G and C:A mismatches it is clearly below 50%. We conclude that the different base-base mismatches are repaired with different efficiencies.
authors.forename: A
authors.initials: A
authors.lastname: Rienitz
authors.forename: F
authors.initials: F
authors.lastname: Grosse
authors.forename: H
authors.initials: H
authors.lastname: Blöcker
authors.forename: R
authors.initials: R
authors.lastname: Frank
authors.forename: G
authors.initials: G
authors.lastname: Krauss
mesh_terms: D000818:Animals; D010584:Bacteriophage phi X 174 / Q000235:genetics*; D001482:Base Composition; D002417:Cattle; D004257:DNA Polymerase II / Q000378:metabolism*; D004260:DNA Repair; D004261:DNA Replication / Q000187:drug effects*; D004279:DNA, Viral / Q000378:metabolism*; D003848:Deoxyguanine Nucleotides / Q000494:pharmacology*; D011756:Diphosphates / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology*; D009154:Mutation; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D013873:Thionucleotides / Q000494:pharmacology*
chemical_list: D004279:DNA, Viral; D003848:Deoxyguanine Nucleotides; D011756:Diphosphates; D013873:Thionucleotides; C021173:2'-deoxy-6-thioguanosine 5'-triphosphate; D008345:Manganese; D004257:DNA Polymerase II