title: Subspecies of DNA polymerase alpha from calf thymus with different fidelity in copying synthetic template-primers.
abstract: Three different subspecies of DNA polymerase alpha from calf thymus sedimenting at 9 S, 7 S and 5.7 S have been investigated with respect to their accuracy of in vitro DNA synthesis on poly (dA) (dT)16 and poly d(AT) as template-primers. Our results indicate that the structure of DNA polymerase alpha has a strong influence on the accuracy of DNA synthesis. The 9 S enzyme shows a misincorporation frequency of about 1:100 000. An error rate of 1:15 000 is measured for the 7 S species. The 5.7 S enzyme for which an error rate of 1:3 000 is determined, has to be considered as error prone. Lowering the rate of DNA synthesis leads to a decrease in fidelity. The single stranded DNA binding protein from E.coli increases the accuracy of the 5.7 S and the 7 S enzyme by a factor of two. Mn2+ decreases the fidelity of all three subspecies in a concentration dependent manner.
mesh_terms: D000818:Animals; D002417:Cattle; D004257:DNA Polymerase II / Q000378:metabolism*; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D007700:Kinetics; D008345:Manganese / Q000494:pharmacology; D013379:Substrate Specificity; D013698:Templates, Genetic; D013950:Thymus Gland / Q000201:enzymology*
chemical_list: D007527:Isoenzymes; D008345:Manganese; D004257:DNA Polymerase II; D004259:DNA-Directed DNA Polymerase