STRUCTURE DETERMINATION OF THE CHD1 DNA-BINDING DOMAIN

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 Chd 1是一种染色质重塑剂，通过操纵核小体结构参与基因转录。通过使核小体沿着DNA滑动，已知Chd 1产生均匀间隔的核小体阵列，并且我们已经发现Chd 1 DNA结合结构域对于感测核小体之间的相对距离是必不可少的。Chd 1 DNA结合结构域以序列非特异性方式结合DNA，目前的问题包括（1）DNA结合结构域如何与核小体核心外的DNA相互作用，（2）结合是否与DNA双链体中的构象变化偶联，以及（3）Chd 1与DNA的结合是否与核小体结合的DNA相容（即促进DNA结合结构域的释放）。我们目前有酵母Chd 1 DNA结合域的晶体与一个12聚体DNA双链体复合，该双链体的分辨率优于2.3埃。我们已经生长了小的SeMet晶体，并希望获得相并解决结构。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Chd1 is a chromatin remodeler that participates in gene transcription by manipulating nucleosome structure. By sliding nucleosomes along DNA, Chd1 is known to generate evenly-spaced nucleosomal arrays, and we have found that the Chd1 DNA-binding domain is essential for sensing the relative distances between nucleosomes. The Chd1 DNA-binding domain binds DNA in a sequence-nonspecific fashion, and current questions include (1) how the DNA-binding domain interacts with DNA just outside the nucleosome core, (2) whether binding is coupled to conformational changes in the DNA duplex, and (3) whether DNA binding by Chd1 would be expected to be compatible with DNA associating with the nucleosome (i.e. promote release of the DNA-binding domain). We currently have crystals of the yeast Chd1 DNA-binding domain in complex with a 12mer DNA duplex that diffract to better than 2.3 angstrom resolution. We have grown small SeMet crystals and hope to obtain phases and solve the structure.