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

点击翻译按钮获取中文摘要

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.