On the fidelity of DNA polymerase alpha: the influence of alpha-thio dNTPs, Mn2+ and mismatch repair.
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.
Rienitz
A
A
Grosse
F
F
Blöcker
H
H
Frank
R
R
Krauss
G
G
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*
D004279:DNA, Viral; D003848:Deoxyguanine Nucleotides; D011756:Diphosphates; D013873:Thionucleotides; C021173:2'-deoxy-6-thioguanosine 5'-triphosphate; D008345:Manganese; D004257:DNA Polymerase II