Error-free bypass of 2-hydroxyadenine by human DNA polymerase lambda with Proliferating Cell Nuclear Antigen and Replication Protein A in different sequence contexts.
Error-free bypass of 2-hydroxyadenine by human DNA polymerase lambda with Proliferating Cell Nuclear Antigen and Replication Protein A in different sequence contexts.
复制标题
人DNA聚合酶lambda对2-羟基趋外的旁路无误通行，并在不同的序列环境中具有增殖细胞核抗原和复制蛋白A的增殖。
DOI：
10.1093/nar/gkm568
复制
发表时间：
2007
影响因子：
14.9
通讯作者：
Maga, Giovanni
中科院分区：
文献类型：
--
作者：
Crespan, Emmanuele;Hubscher, Ulrich;Maga, Giovanni
1，2-二氢-2-氧代腺嘌呤（2-OH-A）是一种常见的由活性氧引起的DNA损伤，是多种DNA聚合酶（DNApols）的强复制阻滞剂。我们以前已经表明，各种碱基可以被错误地掺入2-OH-A病变的对面，并且错误配对的类型随序列背景或测试的DNA pol的类型而变化。在这里，我们分析了人类pol家族X成员DNA pol λ绕过2-OH-A损伤的能力。当病变位于随机序列中时，DNA pol λ可以进行2-OH-A的无错误旁路，而在重复序列背景下，即使旁路也基本上无错误，也可以观察到dGMP的错误掺入。细胞核抗原（PCNA）和复制蛋白A（RP-A）的辅助蛋白增强了DNA pol λ跨损伤合成重复序列2-OH-A的保真度。我们还发现DNA pol λ活性位点残基酪氨酸505决定了对2-OH-A的核苷酸选择性。我们的数据首次表明，2-OH-A损伤可以被人DNA pol λ与PCNA和RP-A的组合有效地和忠实地绕过。
1,2-dihydro-2-oxoadenine (2-OH-A), a common DNA lesion produced by reactive oxygen species, is a strong replicative block for several DNA polymerases (DNA pols). We have previously shown that various bases can be misincorporated opposite the 2-OH-A lesion and the type of mispairs varies with either the sequence context or the type of DNA pol tested. Here, we have analysed the ability of the human pol family X member DNA pol λ, to bypass the 2-OH-A lesion. DNA pol λ can perform error-free bypass of 2-OH-A when this lesion is located in a random sequence, whereas in a repeated sequence context, even though bypass was also largely error-free, misincorporation of dGMP could be observed. The fidelity of translesion synthesis of 2-OH-A in a repeated sequence by DNA pol λ was enhanced by the auxiliary proteins Proliferating Cell Nuclear Antigen (PCNA) and Replication Protein A (RP-A). We also found that the DNA pol λ active site residue tyrosine 505 determined the nucleotide selectivity opposite 2-OH-A. Our data show, for the first time, that the 2-OH-A lesion can be efficiently and faithfully bypassed by a human DNA pol λ in combination with PCNA and RP-A.