Structures of Escherichia coli DNA mismatch repair enzyme MutS in complex with different mismatches:: a common recognition mode for diverse substrates
Structures of Escherichia coli DNA mismatch repair enzyme MutS in complex with different mismatches:: a common recognition mode for diverse substrates
复制标题
DOI：
10.1093/nar/gkg677
复制
发表时间：
2003-08-15
影响因子：
14.9
通讯作者：
Sixma, TK
中科院分区：
文献类型：
--
作者：
Natrajan, G;Lamers, MH;Sixma, TK
我们在G：T、A：A、C：A和G：G错配以及单个未配对胸腺嘧啶核苷的络合物中提纯了一系列大肠杆菌DNA错配修复酶MutS的同构晶体结构。在所有这些结构中，DNA在蛋白质结合时扭结了大约60度。MutS家族中广泛保守的两个残基参与错配识别。可以看到苯丙氨酸，Phe 36，堆积在一个不匹配的碱基上。同样的碱基也可以与谷氨酸38形成氢键。如果Phe 36上的碱基是嘌呤，则这种氢键涉及N7，如果是嘧啶(胸腺嘧啶)，则涉及N3。因此，MutS使用共同的绑定模式来识别广泛的失配。
We have refined a series of isomorphous crystal structures of the Escherichia coli DNA mismatch repair enzyme MutS in complex with G:T, A:A, C:A and G:G mismatches and also with a single unpaired thymidine. In all these structures, the DNA is kinked by similar to60degrees upon protein binding. Two residues widely conserved in the MutS family are involved in mismatch recognition. The phenylalanine, Phe 36, is seen stacking on one of the mismatched bases. The same base is also seen forming a hydrogen bond to the glutamate Glu 38. This hydrogen bond involves the N7 if the base stacking on Phe 36 is a purine and the N3 if it is a pyrimidine (thymine). Thus, MutS uses a common binding mode to recognize a wide range of mismatches.