Reha-Krantz L J, Wong C
Department of Biological Sciences, University of Alberta, Edmonton, Canada.
Mutat Res. 1996 Feb 19;350(1):9-16. doi: 10.1016/0027-5107(95)00085-2.
During DNA replication, DNA polymerases alternate between DNA synthesis and proofreading the newly synthesized DNA. In order to understand the molecular details of how DNA polymerases determine the balance between polymerase and proofreading activities, it would be useful to have mutants which switch between the two activities either more or less frequently. Antimutator DNA polymerases switch more frequently and thus have more opportunity for proofreading. We have observed that mutant DNA polymerases which proofread less frequently have a mutator phenotype and are inhibited by the pyrophosphate analogue phosphonoacetic acid. Sensitivity to phosphonoacetic acid can be used to isolate second-site suppressor mutations. These suppressor mutations encode amino acid substitutions which produce antimutator DNA polymerases.
在DNA复制过程中，DNA聚合酶在DNA合成和校对新合成的DNA之间交替进行。为了了解DNA聚合酶如何确定聚合酶活性和校对活性之间平衡的分子细节，拥有能够更频繁或更不频繁地在这两种活性之间切换的突变体将是很有用的。抗突变DNA聚合酶切换得更频繁，因此有更多的校对机会。我们观察到，校对频率较低的突变DNA聚合酶具有突变体表型，并受到焦磷酸类似物膦酰乙酸的抑制。对膦酰乙酸的敏感性可用于分离第二位点抑制突变。这些抑制突变编码产生抗突变DNA聚合酶的氨基酸取代。
