Chromatin structure revisited.
Chromatin structure revisited.
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DOI：
10.1615/critreveukargeneexpr.v9.i3-4.90
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发表时间：
1999
影响因子：
1.6
通讯作者：
J. Zlatanova;S. Leuba;K. Holde
中科院分区：
文献类型：
--
作者：
J. Zlatanova;S. Leuba;K. Holde
除了我们在理解核心粒子的结构方面取得的巨大进步之外，还有大量的结构问题仍有待回答。这里讨论的主要观点可概括如下：(1)应扩大术语‘核心颗粒’的含义，以反映在染色质纤维的上下文中，包裹在组蛋白八聚体周围的DNA的实际长度可能在约100至约170个碱基之间变化。(2)在染色体中，连接子组蛋白在染色体DNA的一端和靠近二分体轴的一点之间形成了一座桥梁。(3)含有一个HMG1分子的颗粒可归类为真正的染色体。(4)在延伸纤维中，核小体DNA的核心区和连接区的划分是一个动态特征，对环境的影响做出响应；纤维结构相关的约束要求连接区长度超过某个最小值。(5)紧密的纤维结构似乎相当不规则，这种结构的确切性质仍有待确定。最后，术语30 nm纤维应去掉作为致密或浓缩染色质纤维结构的指示符。
Independently of the enormous progress in our understanding of the structure of the core particle, there remain a multitude of structural questions still to be answered. The main points discussed here can be summarized as follows: (1) The meaning of the term 'core particle' should be widened to reflect the fact that the actual length of DNA wrapped around the histone octamer in the context of the chromatin fiber may vary between approximately 100 and approximately 170 bp. (2) In the chromatosome, the linker histone forms a bridge between one terminus of the chromatosomal DNA and a point close to the dyad axis. (3) The particle that contains one molecule of HMG1 may be classified as a bona fide chromatosome. (4) In the extended fiber, the partition of the nucleosomal DNA into core and linker is a dynamic feature, responding to environmental influences; fiber structure-related constraints demand that linker length be beyond a certain minimal value. (5) The compact fiber structure seems to be rather irregular; the precise nature of this structure is still to be determined. Finally, the term 30-nm fiber should be dropped as a designator of the compact or condensed chromatin fiber structure.