库斯A排放的晶体结构表明甲因介导的金属运输
Feng Long1, Chih-Chia Su, Michael T Zimmermann
1Molecular, Cellular and Developmental Biology Interdepartmental Graduate Program, Iowa State University, Iowa 50011, USA.
Nature
|September 25, 2010
概括
对CusA输送器的结构洞察力揭示了Gram负细菌如何使用阻抗结节细胞分裂 (RND) 排泄输出有毒重金属,如铜和银.
科学领域:
- 微生物学 微生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 格拉姆阴性细菌利用RND排泄驱逐有毒化合物.
- 在CusCBA系统中,专门挤出生物制剂Cu (I) 和Ag (I) 离子.
- 对于RND排水的HME子家族,以前没有结构数据.
研究的目的:
- 为了阐明CusA输送器的结构,CusCBA流出系统的关键组件.
- 了解重金属离子结合和CUSA出口的机制.
- 为RND排水的HME子家族提供结构性见解.
主要方法:
- 使用X射线结晶学来确定CUSA的结构.
- 获得的结构是Apo-CusA和CusA与Cu (I) 或Ag (I) 结合.
- 进行了基因分析和运输分析.
主要成果:
- CusA的晶体结构揭示了裂区域中由氨酸集群形成的金属结合部位.
- 周等离子裂在金属结合时从封闭状态转变为开放状态,这表明离子出口途径.
- 金属结合会在Cusa的周等离子体和跨膜领域引发显著的构造变化.
- CusA 具有多个氨酸对/集群,参与金属离子的结合和运输.
结论:
- 库萨结构为RND排水的HME子家族提供了新的见解.
- 为涉及多个 metionin 位点的金属离子运输提出了逐步的穿机制.
- CusA从细菌细胞质中积极结合和输出金属离子.
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