sNASP, a histone H1-specific eukaryotic chaperone dimer that facilitates chromatin assembly
sNASP, a histone H1-specific eukaryotic chaperone dimer that facilitates chromatin assembly
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DOI：
10.1529/biophysj.108.130021
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发表时间：
2008-08-01
影响因子：
3.4
通讯作者：
Ausio, Juan
中科院分区：
文献类型：
--
作者：
Finn, Ron M.;Browne, Kristen;Ausio, Juan
NASP 被描述为哺乳动物中的组蛋白 H1 伴侣。然而，所涉及的分子机制尚未得到表征。在这里，我们证明这种蛋白质不仅存在于哺乳动物中，而且以其体细胞和睾丸形式广泛分布在整个真核生物中。人类体细胞版本的二级结构主要由α-螺旋簇组成，并在溶液中以同二聚体形式存在。该蛋白非特异性结合核心组蛋白 H2A-H2B 二聚体和 H3-H4 四聚体，但仅与组蛋白 H1 形成特异性复合物。 NASP-H1 复合物的形成由组蛋白 H1 的 N 端和 C 端结构域介导，不涉及接头组蛋白特有的翼状螺旋结构域。体外染色质重建实验表明，该蛋白有助于将接头组蛋白掺入核小体阵列上，因此是真正的接头组蛋白伴侣。
NASP has been described as a histone H1 chaperone in mammals. However, the molecular mechanisms involved have not yet been characterized. Here, we show that this protein is not only present in mammals but is widely distributed throughout eukaryotes both in its somatic and testicular forms. The secondary structure of the human somatic version consists mainly of clusters of a-helices and exists as a homodimer in solution. The protein binds nonspecifically to core histone H2A-H2B dimers and H3-H4 tetramers but only forms specific complexes with histone H1. The formation of the NASP-H1 complexes is mediated by the N- and C-terminal domains of histone H1 and does not involve the winged helix domain that is characteristic of linker histones. In vitro chromatin reconstitution experiments show that this protein facilitates the incorporation of linker histones onto nucleosome arrays and hence is a bona fide linker histone chaperone.