Solution structure and DNA-binding properties of the C-terminal domain of UvrC from E.coli
Solution structure and DNA-binding properties of the C-terminal domain of UvrC from E.coli
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DOI：
10.1093/emboj/cdf627
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发表时间：
2002-11-15
期刊：
影响因子：
11.4
通讯作者：
Kaptein, R
中科院分区：
文献类型：
--
作者：
Singh, S;Folkers, GE;Kaptein, R
UvrC蛋白的C末端结构域（UvrC CTD）对于原核核苷酸切除修复过程中的5'切割是必需的。我们使用异核核磁共振技术确定了UvrC CTD的三维结构。该结构显示了由小连接器螺旋连接的两个螺旋-发夹-螺旋（HhH）基序。显示UvrC CTD介导结构特异性DNA结合。该结构域与单链-双链连接DNA结合，对每个环含有至少六个未配对碱基的环状双链体DNA（“气泡DNA”）具有强特异性。使用化学位移扰动实验，DNA结合表面被映射到第一发夹区域，包括保守的甘氨酸-缬氨酸-甘氨酸残基，随后是赖氨酸-精氨酸-精氨酸，带正电荷的表面补丁和由甘氨酸-异亮氨酸-丝氨酸组成的第二发夹区域。蛋白质-DNA复合物的模型提出，占这种特异性。
The C-terminal domain of the UvrC protein (UvrC CTD) is essential for 5' incision in the prokaryotic nucleotide excision repair process. We have determined the three-dimensional structure of the UvrC CTD using heteronuclear NMR techniques. The structure shows two helix-hairpin-helix (HhH) motifs connected by a small connector helix. The UvrC CTD is shown to mediate structure-specific DNA binding. The domain binds to a single-stranded-double-stranded junction DNA, with a strong specificity towards looped duplex DNA that contains at least six unpaired bases per loop ('bubble DNA'). Using chemical shift perturbation experiments, the DNA-binding surface is mapped to the first hairpin region encompassing the conserved glycine-valine-glycine residues followed by lysine-arginine-arginine, a positively charged surface patch and the second hairpin region consisting of glycine-isoleucine-serine. A model for the protein-DNA complex is proposed that accounts for this specificity.