Bacterial EndoMS/NucS acts as a clamp-mediated mismatch endonuclease to prevent asymmetric accumulation of replication errors.
Bacterial EndoMS/NucS acts as a clamp-mediated mismatch endonuclease to prevent asymmetric accumulation of replication errors.
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DOI：
10.1093/nar/gky481
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发表时间：
2018-07-06
影响因子：
14.9
通讯作者：
Miyoshi-Akiyama T
中科院分区：
文献类型：
--
作者：
Takemoto N;Numata I;Su'etsugu M;Miyoshi-Akiyama T
基于mut的错配修复（MMR）系统可消除由复制错误引起的错配。尽管在生命的三个领域中广泛保存着mutS同源物，放线菌和一些古细菌没有与mutS同源的基因。在这里，我们报道了谷氨酰胺棒状杆菌的EndoMS/NucS是与滑动钳合作的失配特异性内切酶。MMR中的EndoMS/NucS功能完全依赖于EndoMS/NucS与滑动钳之间的物理相互作用。endoMS/nucS基因断裂与dnaE突变的结合，降低了DNA聚合酶的保真度，协同提高了突变率，证实了endoMS参与复制纠错。EndoMS在体外特异性切割G/T、G/G和T/T错配，这种底物特异性与全基因组分析中观察到的突变谱一致。观察到的EndoMS的底物特异性，以及EndoMS基因破坏的影响，使我们推测MMR系统，无论系统中的蛋白质类型如何，都能进化到解决不对称发生的复制错误，其中G/T错配比C/A错配发生得更频繁。
Mismatch repair (MMR) systems based on MutS eliminate mismatches originating from replication errors. Despite extensive conservation of mutS homologues throughout the three domains of life, Actinobacteria and some archaea do not have genes homologous to mutS. Here, we report that EndoMS/NucS of Corynebacterium glutamicum is the mismatch-specific endonuclease that functions cooperatively with a sliding clamp. EndoMS/NucS function in MMR was fully dependent on physical interaction between EndoMS/NucS and sliding clamp. A combination of endoMS/nucS gene disruption and a mutation in dnaE, which reduced the fidelity of DNA polymerase, increased the mutation rate synergistically and confirmed the participation of EndoMS in replication error correction. EndoMS specifically cleaved G/T, G/G and T/T mismatches in vitro, and such substrate specificity was consistent with the mutation spectrum observed in genome-wide analyses. The observed substrate specificity of EndoMS, together with the effects of endoMS gene disruption, led us to speculate that the MMR system, regardless of the types of proteins in the system, evolved to address asymmetrically occurring replication errors in which G/T mismatches occur much more frequently than C/A mismatches.
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DOI：
10.1073/pnas.1210309109
发表时间：
2012-10-09
影响因子：
11.1
作者：
Lee, Heewook;Popodi, Ellen;Foster, Patricia L.
通讯作者：
Foster, Patricia L.
影响因子：
5.6
作者：
Fujii, S;Akiyama, M;Maki, H
通讯作者：
Maki, H
影响因子：
1.2
作者：
Inui, M;Kawaguchi, H;Yukawa, H
通讯作者：
Yukawa, H
影响因子：
3.3
作者：
Heilbron K;Toll-Riera M;Kojadinovic M;MacLean RC
通讯作者：
MacLean RC
影响因子：
4.4
作者：
Dettman JR;Sztepanacz JL;Kassen R
通讯作者：
Kassen R