Crucial role and mechanism of transcription-coupled DNA repair in bacteria.
Crucial role and mechanism of transcription-coupled DNA repair in bacteria.
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DOI：
10.1038/s41586-022-04530-6
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发表时间：
2022-04
期刊：
影响因子：
64.8
通讯作者：
中科院分区：
文献类型：
--
作者：
转录偶联DNA修复（TCR）被认为是细菌中核苷酸切除修复（NER）的一个次要子途径。整体基因组修复（GGR）被认为是独立于转录进行大部分修复。TCR也被认为仅由Mfd介导，Mfd是一种边缘NER表型的DNA移位酶。在这里，我们结合在纤维素交联质谱与结构，生物化学和遗传学的方法来映射TCR复合物（TCRC）内的相互作用，并确定导致NER在体内的事件的实际序列。我们证明，RNA聚合酶（RNAP）作为主要的DNA损伤传感器和NER酶的招聘平台。UvrA和UvrD持续与RNAP结合，形成TCRC前的监测。为了应对DNA损伤，前TCRC招募第二个UvrD单体，形成解旋酶活性UvrD二聚体，促进TCRC回溯。UvrD-RNAP相互作用的减弱使细胞对遗传毒性应激敏感。然后，TCRC招募第二个UvrA分子和UvrB来启动修复过程。与传统的教条相反，我们表明TCR占绝大多数的染色体修复事件，即TCR完全主导GGR。我们还表明，TCR在很大程度上是独立的MFD。我们建议，MFD在这个过程中发挥了间接的作用：它参与消除阻塞RNAP在前面的TCRCs，也在恢复TCRCs修复后已经完成的回溯。
Transcription-coupled DNA repair (TCR) is presumed to be a minor sub-pathway of nucleotide excision repair (NER) in bacteria. Global genomic repair (GGR) is thought to perform the bulk of repair independently of transcription. TCR is also believed to be mediated exclusively by Mfd – a DNA translocase of a marginal NER phenotype. Here, we combined in cellulo crosslinking mass spectrometry with structural, biochemical, and genetic approaches to map the interactions within the TCR complex (TCRC) and to determine the actual sequence of events leading to NER in vivo. We demonstrate that RNA polymerase (RNAP) serves as the primary DNA damage sensor and platform for the recruitment of NER enzymes. UvrA and UvrD associate with RNAP continuously, forming a surveillance pre-TCRC. In response to DNA damage, pre-TCRC recruits a second UvrD monomer to form a helicase-competent UvrD dimer that promotes TCRC backtracking. The weakening of UvrD-RNAP interactions renders cells sensitive to genotoxic stress. TCRC then recruits a second UvrA molecule and UvrB to initiate the repair process. Contrary to the conventional dogma, we show that TCR accounts for a vast majority of chromosomal repair events, i.e. TCR thoroughly dominates over GGR. We also show that TCR is largely independent of Mfd. We propose that Mfd plays an indirect role in this process: it participates in removing obstructive RNAPs in front of TCRCs and also in recovering TCRCs from backtracking after repair has been completed.
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影响因子：
14.9
作者：
Duchi D;Mazumder A;Malinen AM;Ebright RH;Kapanidis AN
通讯作者：
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影响因子：
4.7
作者：
Ghosh, Sournitra S.;Kao, Philip M.;Chappelle, Hugh L.
通讯作者：
Chappelle, Hugh L.
影响因子：
2.3
作者：
Carter JD;Labean TH
通讯作者：
Labean TH
影响因子：
--
作者：
Dannenmann B;Lehle S;Lorscheid S;Huber SM;Essmann F;Schulze-Osthoff K
通讯作者：
Schulze-Osthoff K
DOI：
10.1073/pnas.1005203107
发表时间：
2010-08-31
影响因子：
11.1
作者：
Cohen, Susan E.;Lewis, Cindi A.;Walker, Graham C.
通讯作者：
Walker, Graham C.