Dynamic DNA-bound PCNA complexes co-ordinate Okazaki fragment synthesis, processing and ligation.
Dynamic DNA-bound PCNA complexes co-ordinate Okazaki fragment synthesis, processing and ligation.
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DOI：
10.1016/j.jmb.2020.10.032
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发表时间：
2020-12-04
影响因子：
5.6
通讯作者：
Tomkinson AE
中科院分区：
文献类型：
--
作者：
Matsumoto Y;Brooks RC;Sverzhinsky A;Pascal JM;Tomkinson AE
在人类基因组的复制过程中，超过一百万个冈崎片段被合成、加工和连接。在DNA聚合酶α全酶合成RNA-DNA寡核苷酸后，增殖细胞核抗原（PCNA），一种同源三聚体DNA滑动夹和聚合酶持续合成因子，通过复制因子C（RFC）加载到引物-模板连接处。虽然PCNA与DNA聚合酶δ（Pol δ）、瓣状核酸内切酶1（FEN 1）和DNA连接酶I（LigI）相互作用，完成冈崎片段的加工和连接，但尚不清楚这些酶的活性如何协调。在这里，我们描述了一种新的相互作用之间的Pol δ和LigI是冈崎片段连接在体外的关键。LigI和FEN 1在间隙填充合成过程中与PCNA-Pol δ结合，表明间隙填充合成是由PCNA、Pol δ、FEN 1和LigI的复合物进行的。连接后，PCNA和LigI保留在DNA上，表明Pol δ和FEN 1在5'端加工期间解离，并且LigI在由FEN 1和Pol δ产生的DNA切口处接合PCNA。因此，动态PCNA复合物协调Okazaki片段的合成和处理，PCNA和LigI形成环绕连接的DNA的两个连接的蛋白质环的末端结构。
More than a million Okazaki fragments are synthesized, processed and joined during replication of the human genome. After synthesis of an RNA-DNA oligonucleotide by DNA polymerase α holoenzyme, proliferating cell nuclear antigen (PCNA), a homotrimeric DNA sliding clamp and polymerase processivity factor, is loaded onto the primer-template junction by replication factor C (RFC). Although PCNA interacts with the enzymes DNA polymerase δ (Pol δ), flap endonuclease 1 (FEN1) and DNA ligase I (LigI) that complete Okazaki fragment processing and joining, it is not known how the activities of these enzymes are coordinated. Here we describe a novel interaction between Pol δ and LigI that is critical for Okazaki fragment joining in vitro. Both LigI and FEN1 associate with PCNA-Pol δ during gap-filling synthesis, suggesting that gap-filling synthesis is carried out by a complex of PCNA, Pol δ, FEN1 and LigI. Following ligation, PCNA and LigI remain on the DNA, indicating that Pol δ and FEN1 dissociate during 5’ end processing and that LigI engages PCNA at the DNA nick generated by FEN1 and Pol δ. Thus, dynamic PCNA complexes coordinate Okazaki fragment synthesis and processing with PCNA and LigI forming a terminal structure of two linked protein rings encircling the ligated DNA.
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影响因子：
16
作者：
Guo, Zhigang;Kanjanapangka, Julie;Liu, Na;Liu, Songbai;Liu, Changwei;Wu, Zhenxing;Wang, Yingjie;Loh, Tiffany;Kowolik, Claudia;Jamsen, Joonas;Zhou, Mian;Khue Truong;Chen, Yuan;Zheng, Li;Shen, Binghui
通讯作者：
Shen, Binghui
影响因子：
4.8
作者：
Mackey, ZB;Niedergang, C;Tomkinson, AE
通讯作者：
Tomkinson, AE
影响因子：
4.8
作者：
Liu, L;Mo, JY;Lee, MYWT
通讯作者：
Lee, MYWT
真核铅和滞后链DNA聚合酶通过单独的机制加载到引物上，但在PCNA存在下具有可比的加工性。
影响因子：
14.9
作者：
Chilkova O;Stenlund P;Isoz I;Stith CM;Grabowski P;Lundström EB;Burgers PM;Johansson E
通讯作者：
Johansson E
影响因子：
16.6
作者：
Burgers PMJ;Kunkel TA
通讯作者：
Kunkel TA