Mechanism of processivity clamp opening by the delta subunit wrench of the clamp loader complex of E-coli DNA polymerase III
Mechanism of processivity clamp opening by the delta subunit wrench of the clamp loader complex of E-coli DNA polymerase III
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DOI：
10.1016/s0092-8674(01)00462-7
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发表时间：
2001-08-24
期刊：
影响因子：
64.5
通讯作者：
Kuriyan, J
中科院分区：
文献类型：
--
作者：
Jeruzalmi, D;Yurieva, O;Kuriyan, J
E.大肠杆菌DNA聚合酶III（β亚基，真核细胞PCNA的同源物）通过夹加载器γ复合物（真核细胞复制因子C的同源物，RFC）加载到DNA上。β：δ复合物的晶体结构表明，δ在结构上与γ复合物的δ '和γ亚基相关，它是一种分子扳手，可以诱导或捕获β的构象变化，从而使其二聚体界面之一不稳定。结构比较和分子动力学模拟表明，一个弹簧加载的机制，其中的β环打开自发的二聚体界面被扰动的三角扳手。
The dimeric ring-shaped sliding clamp of E. coli DNA polymerase III (beta subunit, homolog of eukaryotic PCNA) is loaded onto DNA by the clamp loader gamma complex (homolog of eukaryotic Replication Factor C, RFC). The delta subunit of the gamma complex binds to the beta ring and opens it. The crystal structure of a beta:delta complex shows that delta, which is structurally related to the delta' and gamma subunits of the gamma complex, is a molecular wrench that induces or traps a conformational change in beta such that one of its dimer interfaces is destabilized. Structural comparisons and molecular dynamics simulations suggest a spring-loaded mechanism in which the beta ring opens spontaneously once a dimer interface is perturbed by the delta wrench.