Multifaceted Recognition of Vertebrate Rev1 by Translesion Polymerases ζ and κ
Multifaceted Recognition of Vertebrate Rev1 by Translesion Polymerases ζ and κ
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DOI：
10.1074/jbc.m112.380998
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发表时间：
2012-07-27
影响因子：
4.8
通讯作者：
Zhou, Pei
中科院分区：
文献类型：
--
作者：
Wojtaszek, Jessica;Liu, Jiangxin;Zhou, Pei
翻译合成是一个基本的生物学过程，它使DNA能够在病变部位复制，以牺牲复制保真度为代价确保遗传信息的及时复制，并且与化疗后癌症耐药的发展有关。真核生物y家族聚合酶Rev1是翻译合成中必不可少的支架蛋白。它的c端结构域（CTD）通过Rev7亚基与翻译聚合酶zeta相互作用，并通过rev1相互作用区（RIR）与脊椎动物中的聚合酶kappa、iota和eta相互作用，是功能的绝对必要条件。我们报道了小鼠Rev1 CTD及其与Pol kappa RIR复合物的第一个溶液结构，揭示了一个非典型的四螺旋束。利用酵母双杂交实验，我们已经确定了rev7结合表面，中心位于Rev1 CTD的α 2- α 3环和α 3的n端一半。小鼠Pol kappa RIR与Rev1 CTD结合诱导无序RIR肽折叠成三转α -螺旋，螺旋由n端帽稳定。RIR结合还诱导Rev1 CTD的无序n端环折叠成β -发夹，该发夹在浅α 1- α 2表面上，并产生一个深疏水腔，与并列在RIR螺旋同侧的基本FF残基相互作用。我们结合结构和生化研究揭示了Rev1 CTD的两个不同表面，它们分别介导延伸和插入翻译聚合酶复合物的组装，并为开发抑制翻译合成的新型癌症治疗方法提供了分子框架。
Translesion synthesis is a fundamental biological process that enables DNA replication across lesion sites to ensure timely duplication of genetic information at the cost of replication fidelity, and it is implicated in development of cancer drug resistance after chemotherapy. The eukaryotic Y-family polymerase Rev1 is an essential scaffolding protein in translesion synthesis. Its C-terminal domain (CTD), which interacts with translesion polymerase zeta through the Rev7 subunit and with polymerases kappa, iota, and eta in vertebrates through the Rev1-interacting region (RIR), is absolutely required for function. We report the first solution structures of the mouse Rev1 CTD and its complex with the Pol kappa RIR, revealing an atypical four-helix bundle. Using yeast two-hybrid assays, we have identified a Rev7-binding surface centered at the alpha 2-alpha 3 loop and N-terminal half of alpha 3 of the Rev1 CTD. Binding of the mouse Pol kappa RIR to the Rev1 CTD induces folding of the disordered RIR peptide into a three-turn alpha-helix, with the helix stabilized by an N-terminal cap. RIR binding also induces folding of a disordered N-terminal loop of the Rev1 CTD into a beta-hairpin that projects over the shallow alpha 1-alpha 2 surface and creates a deep hydrophobic cavity to interact with the essential FF residues juxtaposed on the same side of the RIR helix. Our combined structural and biochemical studies reveal two distinct surfaces of the Rev1 CTD that separately mediate the assembly of extension and insertion translesion polymerase complexes and provide a molecular framework for developing novel cancer therapeutics to inhibit translesion synthesis.