Ministry of Education (MOE) Key Laboratory of Protein Science, Tsinghua University, Beijing 100084, PRC; School of Life Science, Tsinghua University, Beijing 100084, PRC.
Ministry of Education (MOE) Key Laboratory of Protein Science, Tsinghua University, Beijing 100084, PRC; School of Life Science, Tsinghua University, Beijing 100084, PRC; Tsinghua-Peking Joint Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing 100084, PRC.
Trends Biochem Sci. 2020 Mar;45(3):217-227. doi: 10.1016/j.tibs.2019.09.002. Epub 2019 Oct 14.
Chromatin remodelers alter the position and composition of nucleosomes, and play key roles in the regulation of chromatin structure and various chromatin-based transactions. Recent cryo-electron microscopy (cryo-EM) and single-molecule fluorescence resonance energy transfer (smFRET) studies have shed mechanistic light on the fundamental question of how the remodeling enzymes couple with ATP hydrolysis to slide nucleosomes. Structures of the chromatin remodeler Snf2 bound to the nucleosome reveal the conformational cycle of the enzyme and the induced DNA distortion. Investigations on ISWI, Chd1, and INO80 support a unifying fundamental mechanism of DNA translocation. Finally, studies of the SWR1 complex suggest that the enzyme distorts the DNA abnormally to achieve histone exchange without net DNA translocation.
染色质重塑酶改变核小体的位置和组成，并在调控染色质结构和各种基于染色质的反应中发挥关键作用。最近的低温电子显微镜（cryo-EM）和单分子荧光共振能量转移（smFRET）研究为重塑酶如何与 ATP 水解偶联以滑动核小体这一基本问题提供了机制上的见解。与核小体结合的染色质重塑酶 Snf2 的结构揭示了酶的构象循环和诱导的 DNA 扭曲。对 ISWI、Chd1 和 INO80 的研究支持了 DNA 易位的统一基本机制。最后，对 SWR1 复合物的研究表明，该酶通过异常扭曲 DNA 来实现组蛋白交换，而不进行净 DNA 易位。
