Structural basis for proofreading during replication of the Escherichia coli chromosome
Structural basis for proofreading during replication of the Escherichia coli chromosome
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DOI：
10.1016/s0969-2126(02)00738-4
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发表时间：
2002-04-01
期刊：
影响因子：
5.7
通讯作者：
Dixon, NE
中科院分区：
文献类型：
--
作者：
Hamdan, S;Carr, PD;Dixon, NE
大肠杆菌复制DNA聚合酶III的epsilon亚基是校对的3‘-5’核酸外切酶。在两种pH值(5.8和8.5)、分辨率为1.7-1.8埃的条件下，测定了其催化N-末端结构域(086)的结构。蛋白质结构围绕核心的五链贝塔折叠构建，这是DNAQ超家族成员的共同特征。除了TMP和水分子与活性中心的双核金属中心的配位方式不同外，结构是相同的。这些数据被用来开发epsilon的机制，并产生epsilon 186与DNA的络合物的可信模型。
The epsilon subunit of the Escherichia coli replicative DNA polymerase III is the proofreading 3'-5' exonuclease. Structures of its catalytic N-terminal domain (086) were determined at two pH values (5.8 and 8.5) at resolutions of 1.7-1.8 Angstrom, in complex with two Mn(II) ions and a nucleotide product of its reaction, thymidine 5'-monophosphate. The protein structure is built around a core five-stranded beta sheet that is a common feature of members of the DnaQ superfamily. The structures were identical, except for differences in the way TMP and water molecules are coordinated to the binuclear metal center in the active site. These data are used to develop a mechanism for epsilon and to produce a plausible model of the complex of epsilon186 with DNA.