A dimeric viral SET domain methyltransferase specific to Lys27 of histone H3
A dimeric viral SET domain methyltransferase specific to Lys27 of histone H3
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DOI：
10.1038/nsb898
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发表时间：
2003-03-01
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影响因子：
--
通讯作者：
Zhou, MM
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文献类型：
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作者：
Manzur, KL;Farooq, A;Zhou, MM
SET 结构域对组蛋白的位点特异性赖氨酸甲基化是真核生物中基因转录的表观遗传控制的标志。在这里，我们报道来自草履虫小球藻病毒的 SET 结构域蛋白可以特异性地将组蛋白 H3 中的 Lys27 二甲基化，这是一种与基因沉默有关的修饰。病毒SET结构域的溶液结构揭示了与其他已知蛋白质甲基转移酶不同的蝴蝶形头对头对称二聚体。每个亚基由希腊键反平行β-桶和介导二聚体界面的三链开放面三明治组成。辅因子 S-腺苷-L-甲硫氨酸 (SAM) 在 β-桶的开口处结合，C 端氨基酸与 H3 中的 Lys27 以及酶的柔性 C 端尾部中的氨基酸赋予了该病毒组蛋白甲基转移酶的特异性。
Site-specific lysine methylation of histones by SET domains is a hallmark for epigenetic control of gene transcription in eukaryotic organisms. Here we report that a SET domain protein from Paramecium bursaria chlorella virus can specifically di-methylate Lys27 in histone H3, a modification implicated in gene silencing. The solution structure of the viral SET domain reveals a butterfly-shaped head-to-head symmetric dimer different from other known protein methyltransferases. Each subunit consists of a Greek-key antiparallel beta-barrel and a three-stranded open-faced sandwich that mediates the dimer interface. Cofactor S-adenosyl-L-methionine (SAM) binds at the opening of the beta-barrel, and amino acids C-terminal to Lys27 in H3 and in the flexible C-terminal tail of the enzyme confer the specificity of this viral histone methyltransferase.