Identification of a conserved 5'-dRP lyase activity in bacterial DNA repair ligase D and its potential role in base excision repair.
Identification of a conserved 5'-dRP lyase activity in bacterial DNA repair ligase D and its potential role in base excision repair.
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DOI：
10.1093/nar/gkw054
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发表时间：
2016-02-29
影响因子：
14.9
通讯作者：
de Vega M
中科院分区：
文献类型：
--
作者：
de Ory A;Nagler K;Carrasco B;Raguse M;Zafra O;Moeller R;de Vega M
枯草芽孢杆菌是具有非同源末端连接（NHEJ）系统的细菌成员之一，该系统由DNA结合的Ku同二聚体组成，该系统将atp依赖的DNA连接酶D （BsuLigD）招募到双链DNA断裂（DSBs）末端。BsuLigD具有内在的聚合和连接酶活性，使其能够填补断裂末端重新排列后产生的短间隙，并密封由此产生的缺口，有助于在静止期和孢子萌发期间保持基因组的稳定性。在这里，我们发现BsuLigD在n端连接酶区域也具有内在的5 ' -2-脱氧核糖-5-磷酸（dRP）裂解酶活性，该酶与聚合和连接酶活性相协调，可以在体外重构的碱基切除修复（BER）反应中有效修复含2 ' -脱氧尿苷的DNA。在BER中需要聚合、去除dRP和最后的密封步骤，以及BsuLigD与孢子特异性AP内切酶共同参与赋予孢子对超高真空干燥的抗性，表明BsuLigD可能积极参与这一途径。我们证明了dRP裂解酶活性也存在于远亲细菌铜绿假单胞菌的同源蛋白中，使我们能够将我们的结果扩展到其他细菌的ligd。
Bacillus subtilis is one of the bacterial members provided with a nonhomologous end joining (NHEJ) system constituted by the DNA-binding Ku homodimer that recruits the ATP-dependent DNA Ligase D (BsuLigD) to the double-stranded DNA breaks (DSBs) ends. BsuLigD has inherent polymerization and ligase activities that allow it to fill the short gaps that can arise after realignment of the broken ends and to seal the resulting nicks, contributing to genome stability during the stationary phase and germination of spores. Here we show that BsuLigD also has an intrinsic 5′-2-deoxyribose-5-phosphate (dRP) lyase activity located at the N-terminal ligase domain that in coordination with the polymerization and ligase activities allows efficient repairing of 2′-deoxyuridine-containing DNA in an in vitro reconstituted Base Excision Repair (BER) reaction. The requirement of a polymerization, a dRP removal and a final sealing step in BER, together with the joint participation of BsuLigD with the spore specific AP endonuclease in conferring spore resistance to ultrahigh vacuum desiccation suggest that BsuLigD could actively participate in this pathway. We demonstrate the presence of the dRP lyase activity also in the homolog protein from the distantly related bacterium Pseudomonas aeruginosa, allowing us to expand our results to other bacterial LigDs.