当前位置:科学网首页 > 小柯机器人 >详情
RSC复合结合核小体结构获解析
作者:小柯机器人 发布时间:2019/11/1 10:18:02

清华大学陈柱成、北京大学高宁及美国犹他大学医学院Bradley R. Cairns等研究人员合作揭示了与核小体结合的RSC复合体结构。2019年10月31日,国际期刊《科学》在线发表了这一成果。

研究人员报道了酵母RSC结合在核小体上的冷冻电镜结构。RSC被划分为ATP酶马达、肌动蛋白相关蛋白(ARP)模块和底物招募模块(SRM)。RSC主要通过马达与核小体结合,并需要辅亚基Sfh1与H2A-H2B的酸性区域结合,使核小体弹出。SRM被组织成三个底物结合叶,准备结合各自的核小体表位。SRM和马达在核小体上的相对取向解释了RSC对DNA转位和启动子核小体重新定位的方向性。总之,这些发现阐明了RSC的装配和功能,并提供了一个框架来理解哺乳动物同源BAF/PBAF和Sfh1同源INI1/BAF47,它们在癌症中经常发生突变。

据了解,RSC复合物能够重塑染色质并调节基因表达。

附:英文原文
 
Title:Structure of the RSC complex bound to the nucleosome
 
Author:oupi Ye1,2,*, Hao Wu2,3,*, Kangjing Chen1,2, Cedric R. Clapier4, Naveen Verma4, Wenhao Zhang2, Haiteng Deng2, Bradley R. Cairns4,†, Ning Gao5,†, Zhucheng Chen1,2,6,†
 
Issue&Volume:31 Oct 2019
 
Abstract: The RSC complex remodels chromatin structure and regulates gene transcription. We report the cryoEM structure of yeast RSC bound to the nucleosome. RSC is delineated into the ATPase motor, the actin-related-protein (ARP) module, and the substrate-recruitment module (SRM). RSC binds the nucleosome mainly through the motor, with the auxiliary subunit Sfh1 engaging the H2A-H2B acidic patch to enable nucleosome ejection. SRM is organized into three substrate-binding lobes poised to bind their respective nucleosomal epitopes. The relative orientations of the SRM and the motor on the nucleosome explain the directionality of DNA translocation and promoter nucleosome repositioning by RSC. Together, our findings shed light on RSC assembly and functionality, and provide a framework to understand the mammalian homologs BAF/PBAF and the Sfh1 ortholog INI1/BAF47, which are frequently mutated in cancers.
 
DOI:10.1126/science.aay0033

Source:https://science.sciencemag.org/content/early/2019/10/30/science.aay0033

期刊信息
Science:《科学》,创刊于1880年。隶属于美国科学促进会,最新IF:41.037