人体素甲基转移酶SET7/9的结构和催化机制
Bing Xiao1, Chun Jing, Jonathan R Wilson
1Structural Biology Group, National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.
Nature
|January 24, 2003
概括
人类SET7/9是一种独特的单甲基酶,与其他SET蛋白不同. 它的晶体结构揭示了素标和辅因子的结合方式,解释了甲基化特异性和反应机制.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
背景情况:
- 基因组的翻译后修改,包括乙化,酸化和甲基化,调节色素的结构和功能.
- 希斯甲基化主要由SET (Su(var) 3-9,Enhancer-of-zeste,Trithorax) 域酶催化,大多数已知的酶甲基化特定的氨酸残留物.
研究的目的:
- 通过人类SET7/9.9阐明组织素甲基化特异性的结构基础.
- 了解SET7/9介导甲基化及其辅因子相互作用的机制.
- 要将SET7/9描述为一种单甲基酶.
主要方法:
- 一个涉及人类SET7/9的三元复合体的高分辨率晶体结构确定,其中包括一个组胺和辅因子S-adenosyl-l-methionine (AdoMet).
- 溶液研究以确认酶活性和基质特异性.
- 结构分析以确定酶活性部位内的关键相互作用和道.
主要成果:
- 晶体结构显示,组织素基质和AdoMet辅因子与SET7/9.9的相反表面结合.
- 酶内的狭窄通道有助于氨酸侧链进入活性部位和辅因子.
- 证实SET7/9纯属单甲基酶,使其与其他SET蛋白区别开来.
- 该结构为SET7/9对其基因组标的特异性的分子基础提供了洞察力.
结论:
- SET7/9-希斯-AdoMet复合体的结构显示出一种独特的结合模式和道,用于基质访问.
- SET7/9作为一种特定的单甲基酶起作用,其结构特征解释了基质识别和反应机制.
- 这些发现有助于理解SET域蛋白在表观遗传调节中的多样性作用.
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