STRUCTURE DETERMINATION OF THE DNA BINDING DOMAIN OF S CEREVISIAE CHD1 IN COMPL

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 染色质组织是指在真核细胞中包装长片段的DNA，这种结构的基本单位是包裹在~146bp DNA周围的单核小体。DNA的这种结构组织导致重要功能部位(如启动子)的封闭，从而阻碍转录和其他重要的生理事件，如复制和DNA修复。为了促进转录和其他与DNA相关的交易，被称为染色质重塑的酶被招募到核小体中。 然而，染色质结构重塑发生的分步机制还没有被揭开。我们试图通过Chd1来了解染色质重塑的机制，Chd1是一个具有N端双染色域、中央解旋酶样ATPase马达和C端DNA结合域的单体染色质重构体。DNA结合域是一个带有MYB同源区的~275个残基，已被证明以序列非特异性的方式与DNA相互作用。此外，研究表明，DNA结合区对于Chd1的有效重塑至关重要。为了了解酿酒酵母Chd1的DNA结合模块与DNA相互作用的方式，我们将DNA结合结构域与几个寡核苷酸结晶，并确定了该复合体的结构。阐明该复合体的晶体结构将有助于(I)确定该结构域是否有助于与DNA结合时DNA的扭曲，(Ii)有助于绘制与核小体DNA相互作用重要的残基的图谱，(Iii)限制核小体-重塑复合体的模型，以及(Iv)提供对Chd1中结构域通讯的洞察。

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. Chromatin organization pertains to the packaging of long stretches of DNA in eukaryotic cells, with the basic unit of such structure being mono-nucleosomes wrapped around by ~146bp of DNA. This structural organization of DNA leads to leads to the occlusion of functionally important sites (such as promoters), thereby hindering transcription and other crucial physiological events such as replication and DNA repair. In order to facilitate transcription and other DNA-related transactions, enzymes called chromatin-remodelers are recruited to nucleosomes. However, the step-by-step mechanism by which remodeling of chromatin structure occurs is yet to be unraveled. We seek to understand the mechanism of chromatin remodeling using Chd1, a monomeric chromatin remodeler with an N-terminal double chromodomain, a central Helicase-like ATPase motor and a C-terminal DNA binding domain. The DNA binding domain is an ~275 residues stretch with a myb-homology region and has been shown to interact with DNA in a sequence non-specific manner. Additionally, studies have shown that the DNA-binding domain is vital for efficient remodeling by Chd1. In order to understand the manner in which the DNA-binding module of S.cerevisiae Chd1 interacts with DNA, we have crystallized the DNA binding domain in complex with several oligo-nucleotides and seek to determine the structure of the complex. Elucidation of the crystal structure of this complex would(i) help ascertain if this domain aids the distortion of DNA upon binding to it, (ii) facilitate mapping of residues important for interaction with nucleosomal DNA, (iii) restrict models for nucleosome-remodeler complexes, and (iv) provide insight into domain-domain communication in Chd1.