Reckmann B, Krauss G
Nucleic Acids Res. 1986 Mar 11;14(5):2365-80. doi: 10.1093/nar/14.5.2365.
The forward mutation of the lacZ part of the bacteriophage M13mp8 has been used to study the fidelity of the 9S DNA polymerase alpha from calf thymus during in vitro replication of single-stranded DNA. Errors leading to a loss of alpha-complementation were identified by DNA sequencing. The overall mutation rate of the lacZ target sequence was in the range of 1:300-1:1000 which is more than one order of magnitude higher than the spontaneous mutation rate. In a mutL host the mutation rate was nearly threefold higher as compared to the wildtype host. Base substitutions comprise 86% of the errors whereas base deletions amount to 12%. The addition of a base was detected only in one mutant out of 71 sequenced ones. The frameshift mutations occurred predominantly in runs of the same base. The frequencies of individual base substitution are in the order of 2 X 10(-4)-4 X 10(-4) for most of the mismatches. Mutations involving dCTP:T and dGTP:T mismatches are observed with a lower frequency, those involving dTTP:C mismatches with a higher frequency.
噬菌体M13mp8的lacZ部分的正向突变已被用于研究小牛胸腺9S DNA聚合酶α在体外单链DNA复制过程中的保真度。通过DNA测序鉴定导致α互补丧失的错误。lacZ靶序列的总体突变率在1:300 - 1:1000范围内，这比自发突变率高出一个多数量级。在mutL宿主中，突变率比野生型宿主高出近三倍。碱基替换占错误的86%，而碱基缺失占12%。在71个测序的突变体中，仅在一个突变体中检测到碱基添加。移码突变主要发生在相同碱基的重复序列中。大多数错配的单个碱基替换频率约为2×10⁻⁴ - 4×10⁻⁴。涉及dCTP:T和dGTP:T错配的突变观察到的频率较低，涉及dTTP:C错配的频率较高。
