来自Methylomicrobium alcaliphilum的整体膜固醇还原酶的结构
Xiaochun Li1, Rita Roberti2, Günter Blobel1
1Laboratory of Cell Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, New York 10065, USA.
Nature
|October 14, 2014
概括
我们确定了细菌 Δ(14) - 胆固醇还原酶 (MaSR1) 的晶体结构,揭示了其整体膜结构和机制. 这提供了对与先天性疾病相关的人类固醇减少酶的分子洞察力.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 固醇是生命至关重要的分子,通过涉及固醇还原酶的复杂途径合成.
- 关键的固醇还原酶包括Δ(14) -固醇还原酶 (C14SR),7-脱胆固醇还原酶 (DHCR7) 和24-脱胆固醇还原酶 (DHCR24).
- 拉胺B受体 (LBR) 也具有C14SR域,强调了这种酶家族的重要性.
研究的目的:
- 阐明了整体膜固醇减少酶的结构和机制.
- 为人类疾病提供分子洞察力,这些疾病是由DHCR7和LBR.的突变引起的.
主要方法:
- 使用X射线晶体学来确定从含NADPH的Methylomicrobium alcaliphilum 20Z中MaSR1的结构.
- 与可溶性类固醇5β-减少酶进行了生物信息比较.
- 进行了类固醇还原酶活性测试.
主要成果:
- 确定了人类C14SR,DHCR7和LBR的同类物马斯R1的晶体结构.
- MaSR1具有十个跨膜段和一个具有两个相互连接的口袋的催化域,一个是细胞质的,一个是脂质可访问的.
- 结构表明NADPH和固醇基质在口袋结处相互作用.
- MaSR1在胆固醇生物合成中间体上表现出减少酶活性,证实了功能性保存.
结论:
- 马斯R1的结构是完整膜固醇还原酶的原型.
- 这些结构信息为与DHCR7和LBR突变相关的人类疾病的机制提供了分子洞察力.
- 了解这些酶对于破译固醇生物合成和相关疾病至关重要.
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