Solution structure of the methyl-CpG-binding domain of the methylation-dependent transcriptional repressor MBD1
Solution structure of the methyl-CpG-binding domain of the methylation-dependent transcriptional repressor MBD1
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DOI：
10.1093/emboj/18.23.6653
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发表时间：
1999-12-01
期刊：
影响因子：
11.4
通讯作者：
Shirakawa, M
中科院分区：
文献类型：
--
作者：
Ohki, I;Shimotake, N;Shirakawa, M
CPG甲基化在脊椎动物中对于基因沉默、染色质结构改变和基因组稳定性是重要的，并且DNA甲基化状态的差异与印记现象、癌发生和胚胎发育相关。甲基化信号由包含共享甲基-CpG结合结构域（MBD）的蛋白质因子解释。我们已经确定了解决方案的结构MBD的人类甲基化依赖的转录抑制因子MBD 1的多维异谱NR;IR光谱。它折叠成具有特征环的α/β三明治结构。在MBD家族中保守的碱性残基在很大程度上局限于该折叠的一个面和柔性环，它们一起形成大的带正电荷的表面。位点定向诱变和化学位移变化后，与甲基化的DNA络合促进识别该表面的DNA相互作用位点。除了三个碱性残基，保守的Tyr 34和Asp 32被证明是重要的DNA结合。
CPG methylation in vertebrates is important for gene silencing, alterations in chromatin structure and genomic stability, and differences in the DNA-methylation status are correlated with imprinting phenomena, carcinogenesis and embryonic development. Methylation signals are interpreted by protein factors that contain shared methyl-CpG-binding domains (MBDs). We have determined the solution structure of the MBD of the human methylation-dependent transcriptional repressor MBD1 by multi-dimensional heteronuclear NR;IR spectroscopy. It folds into an alpha/beta-sandwich structure with characteristic loops. Basic residues conserved in the MBD family are largely confined to one face of this fold and a flexible loop, which together form a large positively charged surface. Site-directed mutagenesis and chemical shift changes upon complexing with a methylated DNA facilitated identification of this surface as the DNA interaction site. In addition to three basic residues, conserved Tyr34 and Asp32 were shown to be important for the DNA binding.