RPA engages telomeric G-quadruplexes more effectively than CST.
RPA engages telomeric G-quadruplexes more effectively than CST.
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DOI：
10.1093/nar/gkad315
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发表时间：
2023-06-09
影响因子：
14.9
通讯作者：
Wuttke, Deborah S.
中科院分区：
文献类型：
--
作者：
Olson, Conner L.;Barbour, Alexandra T.;Wieser, Thomas A.;Wuttke, Deborah S.
G-四链体(G4S)是一组稳定的二级结构，形成于单链核酸的鸟嘌呤富集区，对DNA的维持构成了挑战。端粒上富含G的DNA序列有形成各种拓扑结构的G4S的倾向。人类蛋白质复合体复制蛋白A(RPA)和CTC1-STN1-TEN1(CST)参与管理端粒上的G4S，导致DNA展开和允许端粒复制进行。在这里，我们使用荧光各向异性平衡结合测量来确定这些蛋白质与各种端粒G4S结合的能力。我们发现，G4S的存在显著抑制了CST与富含G的单链DNA的特异结合能力。相反，RPA与端粒G4S紧密结合，与线性单链DNA相比，与G4结构的亲和力变化可忽略不计。使用突变策略，我们发现RPA DNA结合域共同作用于G4结合，并且同时破坏这些结构域降低了RPA与G4单链DNA的亲和力。CST相对不能破坏G4S，再加上细胞内RPA的丰富，表明RPA可能是负责在端粒分解G4S的主要蛋白质复合体。CST和RPA以不同的倾向结合G-四链体。
G-quadruplexes (G4s) are a set of stable secondary structures that form within guanine-rich regions of single-stranded nucleic acids that pose challenges for DNA maintenance. The G-rich DNA sequence at telomeres has a propensity to form G4s of various topologies. The human protein complexes Replication Protein A (RPA) and CTC1-STN1-TEN1 (CST) are implicated in managing G4s at telomeres, leading to DNA unfolding and allowing telomere replication to proceed. Here, we use fluorescence anisotropy equilibrium binding measurements to determine the ability of these proteins to bind various telomeric G4s. We find that the ability of CST to specifically bind G-rich ssDNA is substantially inhibited by the presence of G4s. In contrast, RPA tightly binds telomeric G4s, showing negligible changes in affinity for G4 structure compared to linear ssDNAs. Using a mutagenesis strategy, we found that RPA DNA-binding domains work together for G4 binding, and simultaneous disruption of these domains reduces the affinity of RPA for G4 ssDNA. The relative inability of CST to disrupt G4s, combined with the greater cellular abundance of RPA, suggests that RPA could act as a primary protein complex responsible for resolving G4s at telomeres. CST and RPA bind G-quadruplexes with differing propensities.
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影响因子：
14.9
作者：
Bhattacharjee A;Wang Y;Diao J;Price CM
通讯作者：
Price CM
影响因子：
64.8
作者：
Chen MC;Tippana R;Demeshkina NA;Murat P;Balasubramanian S;Myong S;Ferré-D'Amaré AR
通讯作者：
Ferré-D'Amaré AR
影响因子：
64.8
作者：
Chen, Liuh-Yow;Redon, Sophie;Lingner, Joachim
通讯作者：
Lingner, Joachim
影响因子：
4.3
作者：
Flynn, Rachel Litman;Chang, Sandy;Zou, Lee
通讯作者：
Zou, Lee
DOI：
10.1007/978-1-61779-480-3_11
发表时间：
2012-01-01
期刊：
PROTEIN NMR TECHNIQUES, THIRD EDITION
影响因子：
--
作者：
Brosey, Chris A.;Chagot, Marie-Eve;Chazin, Walter J.
通讯作者：
Chazin, Walter J.