逐步[FeFe]-酶H集群组件在HydA ((DeltaEFG) 的结构中揭示出来
David W Mulder1, Eric S Boyd, Ranjana Sarma
1Astrobiology Biogeocatalysis Research Center, Montana State University, Bozeman, Montana 59717, USA.
Nature
|April 27, 2010
概括
这项研究揭示了[FeFe]-酶 (HydA) 酶如何组装其活性位点. 它显示,先插入 [4Fe-4S] 集群,然后通过专门的成熟机器插入 2Fe 子集群.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 酶学 是一种酶学.
背景情况:
- 具有Fe-S集群的复杂酶对于碳固定和代谢等过程至关重要.
- 代谢包括[NiFe]-,[FeFe]-和[Fe]-代酶.
- [FeFe]酶活性位点 (H) 有一个 [4Fe-4S] 和一个2Fe子,后者的合成和插入机制尚不清楚.
研究的目的:
- 阐明[FeFe]-化酶中H集群组合的机制.
- 确定H集群组件逐步合成和插入的结构基础.
主要方法:
- A的X射线晶体学 ((DeltaEFG) (缺乏H生物合成基因).
- 生物遗传学分析HydA的演变.
主要成果:
- HydA ((DeltaEFG) 的结构揭示了一个 [4Fe-4S] 集群和一个开放的2Fe子集群口袋.
- 有证据表明,H集群的组装是逐步进行的: [4Fe-4S]被宿主机器插入,随后由2Fe子集群合成并被HydE,HydF和HydG插入.
- 2Fe子集群的插入很可能通过一个短暂的阴离子通道发生.
结论:
- [FeFe]-酶H集群组装是一个逐步的过程.
- A很可能是从一个缺乏2Fe子集群的Nar1类祖先进化而来的,随后在真核生物中获得了.
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