Truglio James J, Rhau Benjamin, Croteau Deborah L, Wang Liqun, Skorvaga Milan, Karakas Erkan, DellaVecchia Matthew J, Wang Hong, Van Houten Bennett, Kisker Caroline
Department of Pharmacological Sciences, State University of New York at Stony Brook, Stony Brook, NY, USA.
EMBO J. 2005 Mar 9;24(5):885-94. doi: 10.1038/sj.emboj.7600568. Epub 2005 Feb 3.
Nucleotide excision repair is a highly conserved DNA repair mechanism present in all kingdoms of life. The incision reaction is a critical step for damage removal and is accomplished by the UvrC protein in eubacteria. No structural information is so far available for the 3' incision reaction. Here we report the crystal structure of the N-terminal catalytic domain of UvrC at 1.5 A resolution, which catalyzes the 3' incision reaction and shares homology with the catalytic domain of the GIY-YIG family of intron-encoded homing endonucleases. The structure reveals a patch of highly conserved residues surrounding a catalytic magnesium-water cluster, suggesting that the metal binding site is an essential feature of UvrC and all GIY-YIG endonuclease domains. Structural and biochemical data strongly suggest that the N-terminal endonuclease domain of UvrC utilizes a novel one-metal mechanism to cleave the phosphodiester bond.
核苷酸切除修复是一种在所有生命王国中都存在的高度保守的DNA修复机制。切割反应是去除损伤的关键步骤,在真细菌中由UvrC蛋白完成。目前尚无关于3' 切割反应的结构信息。在此,我们报告了UvrC N端催化结构域的晶体结构,分辨率为1.5埃,该结构域催化3' 切割反应,并与内含子编码的归巢内切核酸酶GIY-YIG家族的催化结构域具有同源性。该结构揭示了围绕催化镁-水簇的一片高度保守的残基,表明金属结合位点是UvrC和所有GIY-YIG内切核酸酶结构域的一个基本特征。结构和生化数据强烈表明,UvrC的N端内切核酸酶结构域利用一种新型的单金属机制来切割磷酸二酯键。