Accuracy of thymine-thymine dimer bypass by Saccharomyces cerevisiae DNA polymerase eta.
Accuracy of thymine-thymine dimer bypass by Saccharomyces cerevisiae DNA polymerase eta.
复制标题
酿酒酵母 DNA 聚合酶 eta 绕过胸腺嘧啶-胸腺嘧啶二聚体的准确性。
DOI：
10.1073/pnas.97.7.3094
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发表时间：
2000
影响因子：
11.1
通讯作者：
Prakash,L
中科院分区：
文献类型：
--
作者：
Washington,MT;Johnson,RE;Prakash,S;Prakash,L
酿酒酵母RAD30基因在紫外线损伤DNA的无错复制中起作用。RAD30编码一种DNA聚合酶Polη，它插入两个腺嘌呤，与腺苷-合成胸腺嘧啶-胸腺嘧啶(T-T)二聚体相对。在这里，我们使用稳态动力学来确定与T-T二聚体相反的DNA合成的准确性。令人惊讶的是，与损伤相对的DNA合成的准确性与相对的未损伤的DNA几乎没有区别，错误掺入的频率约为10−2到10−3。这些研究支持这样的假设，即与大多数DNA聚合酶不同，PolLη能够耐受损伤导致的DNA扭曲，从而使聚合酶能够利用T-T二聚体的内在碱基配对能力。
TheSaccharomyces cerevisiae RAD30gene functions in error-free replication of UV-damaged DNA.RAD30encodes a DNA polymerase, Pol η, which inserts two adenines opposite the two thymines of acis-synthymine–thymine (T–T) dimer. Here we use steady-state kinetics to determine the accuracy of DNA synthesis opposite the T–T dimer. Surprisingly, the accuracy of DNA synthesis opposite the damaged DNA is nearly indistinguishable from that opposite nondamaged DNA, with frequencies of misincorporation of about 10−2to 10−3. These studies support the hypothesis that unlike most DNA polymerases, Pol η is able to tolerate distortions in DNA resulting from damage, which then enables the polymerase to utilize the intrinsic base pairing ability of the T–T dimer.