Complex formation with Rev1 enhances the proficiency of Saccharomyces cerevisiae DNA polymerase for mismatch extension and for extension opposite from DNA lesions
Complex formation with Rev1 enhances the proficiency of Saccharomyces cerevisiae DNA polymerase for mismatch extension and for extension opposite from DNA lesions
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DOI：
10.1128/mcb.01671-06
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发表时间：
2006-12-01
影响因子：
5.3
通讯作者：
Prakash, Louise
中科院分区：
文献类型：
--
作者：
Acharya, Narottam;Johnson, Robert E.;Prakash, Louise
Rev 1是一种Y家族DNA聚合酶（Pol），它与Pol zeta（一种由Rev 3催化亚基和Rev 7辅助亚基组成的B家族Pol）一起促进跨损伤DNA合成（TLS）。对酿酒酵母的广泛遗传研究表明，Pol和Rev 1都需要损伤诱导的诱变，这意味着它们参与了诱变TLS。Pole特别适合促进病变绕过的延伸步骤，因为它可以熟练地延伸DNA病变对面的引物末端，而且它也是未受损DNA上错配引物末端的熟练延伸剂。由于TLS通过UV诱导的损伤和各种其他DNA损伤不依赖于Rev 1的DNA合成活性，Rev 1必须以非酶促方式促成Pol-dependent TLS。在这里，我们提供的证据Rev 1与Pol的物理关联，并表明这种结合是通过Rev 1的C末端和Rev 3的聚合酶结构域介导的。重要的是，缺乏抑制与Rev 3相互作用的C-末端72个残基的rev 1突变体表现出与rev 1 Delta突变所赋予的相同的高度UV敏感性和UV诱导诱变缺陷。我们建议，Rev 1结合Pol是必不可少的目标Pol的复制叉停滞在DNA损伤。除了这种结构的作用，Rev 1的结合增强了Pol的能力，为未受损的DNA上的错配引物末端的延伸和引物末端相对DNA损伤的延伸。
Rev1, a Y family DNA polymerase (Pol) functions together with Pol zeta, a B family Pol comprised of the Rev3 catalytic subunit and Rev7 accessory subunit, in promoting translesion DNA synthesis (TLS). Extensive genetic studies with Saccharomyces cerevisiae have indicated a requirement of both Pol and Rev1 for damage-induced mutagenesis, implicating their involvement in mutagenic TLS. Pole is specifically adapted to promote the extension step of lesion bypass, as it proficiently extends primer termini opposite DNA lesions, and it is also a proficient extender of mismatched primer termini on undamaged DNAs. Since TLS through UV-induced lesions and various other DNA lesions does not depend upon the DNA-synthetic activity of Rev1, Rev1 must contribute to Pol-dependent TLS in a nonenzymatic way. Here, we provide evidence for the physical association of Rev1 with Pol and show that this binding is mediated through the C terminus of Rev1 and the polymerase domain of Rev3. Importantly, a rev1 mutant that lacks the C-terminal 72 residues which inactivate interaction with Rev3 exhibits the same high degree of UV sensitivity and defectiveness in UV-induced mutagenesis as that conferred by the rev1 Delta mutation. We propose that Rev1 binding to Pol is indispensable for the targeting of Pol to the replication fork stalled at a DNA lesion. In addition to this structural role, Rev1 binding enhances the proficiency of Pol for the extension of mismatched primer termini on undamaged DNAs and for the extension of primer termini opposite DNA lesions.