Brosius S, Grosse F, Krauss G
Nucleic Acids Res. 1983 Jan 11;11(1):193-202. doi: 10.1093/nar/11.1.193.
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.
对小牛胸腺中沉降系数分别为9S、7S和5.7S的三种不同亚种的DNA聚合酶α，就其以聚（dA）（dT）16和聚d（AT）作为模板引物进行体外DNA合成的准确性进行了研究。我们的结果表明，DNA聚合酶α的结构对DNA合成的准确性有很大影响。9S酶的错误掺入频率约为1:100 000。7S亚种的错误率为1:15 000。5.7S酶的错误率为1:3 000，必须被视为易出错的。降低DNA合成速率会导致保真度下降。来自大肠杆菌的单链DNA结合蛋白使5.7S和7S酶的准确性提高了两倍。Mn2+以浓度依赖的方式降低了所有三个亚种的保真度。
