Interaction of DNA polymerase and DNA helicase within the bacteriophage T4 DNA replication complex. Leading strand synthesis by the T4 DNA polymerase mutant A737V (tsL141) requires the T4 gene 59 helicase assembly protein.
Interaction of DNA polymerase and DNA helicase within the bacteriophage T4 DNA replication complex. Leading strand synthesis by the T4 DNA polymerase mutant A737V (tsL141) requires the T4 gene 59 helicase assembly protein.
复制标题
噬菌体 T4 DNA 复制复合物中 DNA 聚合酶和 DNA 解旋酶的相互作用。
DOI：
10.1016/s0021-9258(17)42371-4
复制
发表时间：
1994
期刊：
影响因子：
--
通讯作者：
N. G. Nossal
中科院分区：
文献类型：
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作者：
P. Spacciapoli;N. G. Nossal
T4 DNA聚合酶中的噬菌体T4 tsL 141（A737 V）突变体对DNA复制是温度敏感的，并且对某些类型的突变是抗突变剂。在随附的论文（Spacciapoli，P.，和Nossal，N. G.（1993）J.Biol.Chem.269，438-446），我们表明纯化的A737 V T4 DNA聚合酶作为聚合酶比野生型酶的加工性低，但作为核酸外切酶的加工性高。用A737 V突变体聚合酶重建的噬菌体T4多酶复制复合物在滞后链和前导链合成中都有缺陷。在滞后链模板上，A737 V聚合酶被基因44/62和45聚合酶辅助蛋白和基因32 DNA结合蛋白刺激，但仍然比野生型更频繁地在暂停位点被阻止。与野生型T4 DNA聚合酶相反，A737 V聚合酶不催化具有聚合酶辅助蛋白、32蛋白和基因41蛋白解旋酶的分叉双链体模板上的前导链合成。A737 V聚合酶需要T4基因59解旋酶组装蛋白以及其他蛋白质来进行该反应。这些缺陷中的每一个都被基因内L771 F突变抑制，该突变在体内抑制A737 V聚合酶的抗突变体表型（Reha-Krantz，L. J.，Stocki，S.，诺奈河和Maughan，C.等人（1989）J. Cell. 13D，140）。
The bacteriophage T4 tsL141 (A737V) mutant in T4 DNA polymerase is temperature-sensitive for DNA replication and an antimutator for some types of mutations. In the accompanying paper (Spacciapoli, P., and Nossal, N. G. (1993) J. Biol. Chem. 269, 438-446), we show that the purified A737V T4 DNA polymerase is less processive than the wild type enzyme as a polymerase, but is more processive as an exonuclease. The bacteriophage T4 multienzyme replication complex reconstituted with the A737V mutant polymerase is defective in both lagging and leading strand synthesis. On lagging strand templates, the A737V polymerase is stimulated by the gene 44/62 and 45 polymerase accessory proteins and the gene 32 DNA binding protein, but is still arrested at pause sites much more frequently than the wild type. In contrast to wild type T4 DNA polymerase, the A737V polymerase does not catalyze leading strand synthesis on a forked duplex template with the polymerase accessory proteins, 32 protein, and the gene 41 protein helicase. The A737V polymerase requires the T4 gene 59 helicase assembly protein, as well as the other proteins, to carry out this reaction. Each of these defects is suppressed by the intragenic L771F mutation that suppresses the antimutator phenotype of the A737V, polymerase in vivo (Reha-Krantz, L. J., Stocki, S., Nonay, R., and Maughan, C. (1989) J. Cell. Biochem. 13D, 140).