Solution structure of the matrix attachment region-binding domain of chicken MeCP2
Solution structure of the matrix attachment region-binding domain of chicken MeCP2
复制标题
DOI：
10.1046/j.1432-1033.2003.03714.x
复制
发表时间：
2003-08-01
期刊：
影响因子：
--
通讯作者：
Brunner, E
中科院分区：
文献类型：
--
作者：
Heitmann, B;Maurer, T;Brunner, E
甲基CpG结合蛋白2(MeCP2)是一种多功能蛋白质，参与染色质的组织和甲基化DNA的沉默。MAR-BD是鸡MeCP2(cMeCP2，最初命名为ARBP)的125个氨基酸残基，是识别MAR元件和小鼠卫星DNA所需的最小蛋白质片段。在这里，我们报告了MAR-BD的多维异核核磁共振波谱测定的溶液结构。该结构域的全局折叠非常类似于大鼠MeCP2 MBD和MBD1MBD(分别是大鼠MeCP2和甲基CpG结合结构域蛋白1的甲基-CpG结合域)，表现出一个三链反平行的β-折叠和一个α-螺旋(1)。我们发现MAR-BD的C-末端还含有一个两亲性螺旋线圈，即α(2)/α(3)。该线圈的亲水残基形成一个与DNA界面相对的表面，可与MeCP2或其他蛋白质的其他结构域相互作用。对MAR-BD与小鼠卫星DNA高亲和力结合位点的15个碱基片段形成的络合物的光谱研究表明，COIL也参与了蛋白质和DNA的相互作用。这些研究为讨论在Rett综合征病例中发现的螺旋线圈内的六个错义突变的后果提供了基础。
Methyl-CpG-binding protein 2 (MeCP2) is a multifunctional protein involved in chromatin organization and silencing of methylated DNA. MAR-BD, a 125-amino-acid residue domain of chicken MeCP2 (cMeCP2, originally named ARBP), is the minimal protein fragment required to recognize MAR elements and mouse satellite DNA. Here we report the solution structure of MAR-BD as determined by multidimensional heteronuclear NMR spectroscopy. The global fold of this domain is very similar to that of rat MeCP2 MBD and MBD1 MBD (the methyl-CpG-binding domains of rat MeCP2 and methyl-CpG-binding domain protein 1, respectively), exhibiting a three-stranded antiparallel beta-sheet and an alpha-helix alpha(1) . We show that the C-terminal portion of MAR-BD also contains an amphipathic helical coil, alpha(2) /alpha(3) . The hydrophilic residues of this coil form a surface opposite the DNA interface, available for interactions with other domains of MeCP2 or other proteins. Spectroscopic studies of the complex formed by MAR-BD and a 15-bp fragment of a high-affinity binding site from mouse satellite DNA indicates that the coil is also involved in protein.DNA interactions. These studies provide a basis for discussion of the consequences of six missense mutations within the helical coil found in Rett syndrome cases.