Sanders Kelly, Lin Chia-Liang, Smith Abigail J, Cronin Nora, Fisher Gemma, Eftychidis Vasileios, McGlynn Peter, Savery Nigel J, Wigley Dale B, Dillingham Mark S
DNA:Protein Interactions Unit, School of Biochemistry, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, UK.
Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, UK and Section of Structural Biology, Department of Medicine, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
Nucleic Acids Res. 2017 Apr 20;45(7):3875-3887. doi: 10.1093/nar/gkx074.
The PcrA/UvrD helicase functions in multiple pathways that promote bacterial genome stability including the suppression of conflicts between replication and transcription and facilitating the repair of transcribed DNA. The reported ability of PcrA/UvrD to bind and backtrack RNA polymerase (1,2) might be relevant to these functions, but the structural basis for this activity is poorly understood. In this work, we define a minimal RNA polymerase interaction domain in PcrA, and report its crystal structure at 1.5 Å resolution. The domain adopts a Tudor-like fold that is similar to other RNA polymerase interaction domains, including that of the prototype transcription-repair coupling factor Mfd. Removal or mutation of the interaction domain reduces the ability of PcrA/UvrD to interact with and to remodel RNA polymerase complexes in vitro. The implications of this work for our understanding of the role of PcrA/UvrD at the interface of DNA replication, transcription and repair are discussed.
PcrA/UvrD解旋酶在多种促进细菌基因组稳定性的途径中发挥作用，包括抑制复制与转录之间的冲突以及促进转录DNA的修复。报道的PcrA/UvrD结合并回溯RNA聚合酶的能力（1,2）可能与这些功能相关，但这种活性的结构基础尚不清楚。在这项工作中，我们定义了PcrA中一个最小的RNA聚合酶相互作用结构域，并报告了其1.5埃分辨率的晶体结构。该结构域采用类Tudor折叠，与其他RNA聚合酶相互作用结构域相似，包括原型转录修复偶联因子Mfd的结构域。相互作用结构域的去除或突变会降低PcrA/UvrD在体外与RNA聚合酶复合物相互作用并对其进行重塑的能力。本文讨论了这项工作对于我们理解PcrA/UvrD在DNA复制、转录和修复界面上的作用的意义。
