Fast, long-range, reversible conformational fluctuations in nucleosomes revealed by single-pair fluorescence resonance energy transfer
Fast, long-range, reversible conformational fluctuations in nucleosomes revealed by single-pair fluorescence resonance energy transfer
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DOI：
10.1073/pnas.0500189102
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发表时间：
2005-03-01
影响因子：
11.1
通讯作者：
Leuba, SH
中科院分区：
文献类型：
--
作者：
Tomschik, M;Zheng, HC;Leuba, SH
核小体核心颗粒是染色质纤维中的基本重复结构，由8个核心组蛋白分子组成的八聚体组成，分为二聚体(H_2A/H_2B)和四聚体[(H_3/H_4)(2)]，DNA以几乎两个左旋转角紧紧包裹在它们周围。核小体必须经历一定的构象变化，才能发生需要接触DNA模板的过程。通过单对荧光共振能量转移，我们展示了核小体在两种状态之间快速、长期、可逆的构象波动：完全折叠(关闭)，DNA包裹在组蛋白核心周围，或者开放，DNA从组蛋白八聚体显著解体。进入延长开放状态的短暂漂移可能会为DNA交易中涉及的蛋白质因子结合或沿DNA移位创造机会之窗。
The nucleosome core particle, the basic repeated structure in chromatin fibers, consists of an octamer of eight core histone molecules, organized as dimers (H2A/H2B) and tetramers [(H3/ H4)(2)] around which DNA wraps tightly in almost two left-handed turns. The nucleosome has to undergo certain conformational changes to allow processes that need access to the DNA template to occur. By single-pair fluorescence resonance energy transfer, we demonstrate fast, long-range, reversible conformational fluctuations in nucleosomes between two states: fully folded (closed), with the DNA wrapped around the histone core, or open, with the DNA significantly unraveled from the histone octamer. The brief excursions into an extended open state may create windows of opportunity for protein factors involved in DNA transactions to bind to or translocate along the DNA.