On the fidelity of DNA polymerase α: the influence of α-thio dNTPs, Mn2+ and mismatch repair

• Published in: Nucleic acids research Vol. 13; no. 15; pp. 5685 - 5695
• Main Authors: Rienitz, Axel, Grosse, Frank, Blöcker, Helmut, Frank, Ronald, Krauss, Gerhard
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 12-08-1985
• Subjects: Animals; Bacteriophage phi X 174 - genetics; Base Composition; Biological and medical sciences; Cattle; Deoxyguanine Nucleotides - pharmacology; Diphosphates - pharmacology; DNA Polymerase II - metabolism; DNA Repair; DNA Replication - drug effects; DNA, Viral - metabolism; Fundamental and applied biological sciences. Psychology; Manganese - pharmacology; Molecular and cellular biology; Molecular genetics; Mutation; Replication; Structure-Activity Relationship; Substrate Specificity; Thionucleotides - pharmacology; Thymus gland; Error; Manganese II; Base pairing; Biological activity; Vertebrata; Mammalia; DNA polymerase α; In vitro replication; Artiodactyla; Beef; Repair; Ungulata
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/13.15.5685

The Ф X174aml6 revertant system has been used to investigate the influence of α -thio-dNTPs and of Mn2+ on the fidelity of the 9S DNA polymerase α from calf thymus. Upon substituting dGTP by α-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 α-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 Ф Xaml6 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.