Chemical Synthesis of K34-Ubiquitylated H2B for Nucleosome Reconstitution and Single-Particle Cryo-Electron Microscopy Structural Analysis
Chemical Synthesis of K34-Ubiquitylated H2B for Nucleosome Reconstitution and Single-Particle Cryo-Electron Microscopy Structural Analysis
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用于核小体重建和单颗粒冷冻电子显微镜结构分析的 K34-泛素化 H2B 的化学合成
DOI：
10.1002/cbic.201600551
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发表时间：
2017
期刊：
影响因子：
3.2
通讯作者：
Tian Changlin
中科院分区：
文献类型：
--
作者：
Li Jiabin;He Qiaoqiao;Liu Yuntao;Liu Sanling;Tang Shan;Li Chengmin;Sun Demeng;Li Xiaorun;Zhou Min;Zhu Ping;Bi Guoqiang;Zhou Zhenghong;Zheng Ji-Shen;Tian Changlin
Post‐translational modifications (e.g., ubiquitylation) of histones play important roles in dynamic regulation of chromatin. Histone ubiquitylation has been speculated to directly influence the structure and dynamics of nucleosomes. However, structural information for ubiquitylated nucleosomes is still lacking. Here we report an alternative strategy for total chemical synthesis of homogenous histone H2B‐K34‐ubiquitylation (H2B‐K34Ub) by using acid‐cleavable auxiliary‐mediated ligation of peptide hydrazides for site‐specific ubiquitylation. Synthetic H2B‐K34Ub was efficiently incorporated into nucleosomes and further used for single‐particle cryo‐electron microscopy (cryo‐EM) imaging. The cryo‐EM structure of the nucleosome containing H2B‐K34Ub suggests that two flexible ubiquitin domains protrude between the DNA chains of the nucleosomes. The DNA chains around the H2B‐K34 sites shift and provide more space for ubiquitin to protrude. These analyses indicated local and slight structural influences on the nucleosome with ubiquitylation at the H2B‐K34 site.
