当前位置:科学网首页 > 小柯机器人 >详情
RNAPII与FACT延伸复合物对核糖体拆解和重新组装的结构基础获解析
作者:小柯机器人 发布时间:2022/8/21 23:01:03

日本理化学研究所Shun-ichi Sekine、Hitoshi Kurumizaka等研究人员,合作揭示RNAPII与FACT延伸复合物对核糖体拆解和重新组装的结构基础。2022年8月18日,《科学》杂志在线发表了这项成果。

利用冷冻电镜,研究人员获得了在转录延伸因子Spt6、Spn1、Elf1、Spt4/5、Paf1C和组蛋白伴侣FACT的存在下,RNA聚合酶II(RNAPII)延伸复合体(EC)穿过核糖体的结构。这些结构显示了EC在DNA上延伸,介导下游核糖体的分解,然后在FACT的推动下在EC上游重新组装的快照。FACT动态地适应相继发生的亚核糖体中间产物,与EC形成一个界面。Spt6、Spt4/5和Paf1C在EC的DNA出口处形成一个"摇篮",并支持上游核糖体的重新组装。

这些结构解释了EC穿越核糖体同时保持染色质结构和表观遗传信息的机制。

据介绍,在基因转录过程中,RNAPII会穿越染色质中的核糖体,但其机制仍然难以捉摸。

附:英文原文

Title: Structural basis of nucleosome disassembly and reassembly by RNAPII elongation complex with FACT

Author: Haruhiko Ehara, Tomoya Kujirai, Mikako Shirouzu, Hitoshi Kurumizaka, Shun-ichi Sekine

Issue&Volume: 2022-08-18

Abstract: During gene transcription, RNA polymerase II (RNAPII) traverses nucleosomes in chromatin, but its mechanism has remained elusive. Using cryo-electron microscopy, we obtained structures of the RNAPII elongation complex (EC) passing through a nucleosome, in the presence of transcription elongation factors Spt6, Spn1, Elf1, Spt4/5, and Paf1C and the histone chaperone FACT. The structures show snapshots of EC progression on DNA, mediating downstream nucleosome disassembly followed by its reassembly upstream of the EC, facilitated by FACT. FACT dynamically adapts to successively occurring subnucleosome intermediates, forming an interface with the EC. Spt6, Spt4/5, and Paf1C form a “cradle” at the EC DNA-exit site, and support the upstream nucleosome reassembly. These structures explain the mechanism by which the EC traverses nucleosomes while maintaining the chromatin structure and epigenetic information.

DOI: abp9466

Source: https://www.science.org/doi/10.1126/science.abp9466

 

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