XRCC1 interaction with the REV1 C-terminal domain suggests a role in post replication repair
XRCC1 interaction with the REV1 C-terminal domain suggests a role in post replication repair
复制标题
DOI：
10.1016/j.dnarep.2013.08.015
复制
发表时间：
2013-12-01
期刊：
影响因子：
3.8
通讯作者：
London, Robert E.
中科院分区：
文献类型：
--
作者：
Gabel, Scott A.;DeRose, Eugene F.;London, Robert E.
X射线交叉互补基团1蛋白(XRCC1)是一种与DNA修复酶结合的支架，参与单链断裂和碱基切除修复，要求它被招募到DNA损伤的部位。然而，目前对这一招聘的结构性洞察有限。对XRCC1的第一个非结构连接器域的序列分析确定了一个与可能的Rev1相互作用区(X1RIR)基序一致的片段。X1RIR基序存在于跨损伤聚合酶中，该聚合酶可以通过与Rev1 C末端结构域的特异性相互作用而被招募到PolZeta/Rev1 DNA修复复合体中。对含有该RIR基序的XRCC1衍生多肽进行了核磁共振和荧光滴定研究，以评估其与Rev1 C末端结构域的结合亲和力。这些研究证明了XRCC1衍生的多肽与人Rev1 C末端结构域的相互作用，其特征是解离常数在低微摩尔范围内。比较XRCC1RIR多肽和以前研究的RIR多肽的配基竞争研究发现与基于核磁共振的K-d值不一致。这些差异是通过使用荧光分析来解决的，RIR-Rev1系统特别适合于这种分析。通过NOE限制将未标记的XRCC1多肽与标记的Rev1 C末端结构域对接，确定了Rev1-XRCC1多肽复合体的结构。尽管XRCC1中的螺旋片段比在这些情况下观察到的要短，但XRCC1的结构通常与先前确定的Polkappa和polETA rir多肽的复合物同源。这些研究提示XRCC1及其相关的修复因子可能参与了复制后修复。爱思唯尔出版公司(Elsevier B.V.)
The function of X-ray cross complementing group 1 protein (XRCC1), a scaffold that binds to DNA repair enzymes involved in single-strand break and base excision repair, requires that it be recruited to sites of damaged DNA. However, structural insights into this recruitment are currently limited. Sequence analysis of the first unstructured linker domain of XRCC1 identifies a segment consistent with a possible REV1 interacting region (X1RIR) motif. The X1RIR motif is present in translesion polymerases that can be recruited to the pol zeta/REV1 DNA repair complex via a specific interaction with the REV1 C-terminal domain. NMR and fluorescence titration studies were performed on XRCC1-derived peptides containing this putative RIR motif in order to evaluate the binding affinity for the REV1 C-terminal domain. These studies demonstrate an interaction of the XRCC1-derived peptide with the human REV1 C-terminal domain characterized by dissociation constants in the low micromolar range. Ligand competition studies comparing the XRCC1 RIR peptide with previously studied RIR peptides were found to be inconsistent with the NMR based K-d values. These discrepancies were resolved using a fluorescence assay for which the RIR-REV1 system is particularly well suited. The structure of a REV1-XRCC1 peptide complex was determined by using NOE restraints to dock the unlabeled XRCC1 peptide with a labeled REV1 C-terminal domain. The structure is generally homologous with previously determined complexes with the pol kappa and pol eta RIR peptides, although the helical segment in XRCC1 is shorter than was observed in these cases. These studies suggest the possible involvement of XRCC1 and its associated repair factors in post replication repair. Published by Elsevier B.V.