Dynamics of translesion DNA synthesis catalyzed by the bacteriophage T4 exonuclease-deficient DNA polymerase
Dynamics of translesion DNA synthesis catalyzed by the bacteriophage T4 exonuclease-deficient DNA polymerase
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DOI：
10.1021/bi0101594
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发表时间：
2001-06-19
期刊：
影响因子：
2.9
通讯作者：
Berdis, AJ
中科院分区：
文献类型：
--
作者：
Berdis, AJ
使用含有旨在模拟脱碱基位点的四氢呋喃部分的引物/模板来评估跨损伤DNA合成的机制和动力学。稳态动力学分析表明，T4 DNA 聚合酶优先从脱碱基位点整合 dATP，效率比其他三磷酸核苷高 100 倍。在稳态条件下，脱碱基位点上 dATP 掺入的催化效率仅比 T 上的催化效率低 220 倍。令人惊讶的是，T 上的错误掺入比脱碱基位点上复制的催化效率高 4-6 倍，这表明聚合循环的动力学受到异常碱基对形成的不同影响，而不是脱碱基提供的碱基配对能力的缺乏。 地点。获得了从无碱基位点掺入任何 dNTP 的线性前稳态时间过程，表明化学或化学之前的步骤是聚合循环的速率限制。低元素影响（
The mechanism and dynamics of translesion DNA synthesis were evaluated using primer/templates containing a tetrahydrofuran moiety designed to mimic an abasic site. Steady-state kinetic analysis reveals that the T4 DNA polymerase preferentially incorporates dATP across from the abasic site with 100-fold higher efficiency than the other nucleoside triphosphates. Under steady-state conditions, the catalytic efficiency of dATP incorporation across from an abasic site is only 220-fold lower than that across from T. Surprisingly, misincorporation across from T is favored 4-6-fold versus replication across an abasic site, suggesting that the dynamics of the polymerization cycle are differentially affected by formation of aberrant base pairs as opposed to the lack of base-pairing capabilities afforded by the abasic site. Linear pre-steady-state time courses were obtained for the incorporation of any dNTP across from an abasic site, indicating that chemistry or a step prior to chemistry is rate-limiting for the polymerization cycle. Low elemental effects (