呼吸系统复合体I的膜域结构
Rouslan G Efremov1, Leonid A Sazanov
1Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK.
Nature
|August 9, 2011
概括
大肠杆菌复合体I膜域的晶体结构揭示了关键子单元中的新型抗载体类折叠. 这种结构阐明了独特的质子转位途径,涉及六个元素的 lysines 和协调的 conformational 变化.
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:
- 复合物I是细胞能量生产中的关键酶,与神经退行性疾病有关.
- 该酶包括水友和膜域;水友域结构之前已经确定.
- 了解膜域结构对于理解质子转位机制至关重要.
研究的目的:
- 为了确定大肠杆菌复合体I膜域的晶体结构.
- 阐明复合体I中质子转位的结构基础.
- 识别关键子单元及其在膜域中的作用.
主要方法:
- 在3.0 Å分辨率的X射线晶体学.
- 对六个子单元的膜域 (NuoL, NuoM, NuoN, NuoA, NuoJ, NuoK) 的分析.
- 跨膜螺旋和残留网络的结构分析.
主要成果:
- 报告了大肠杆菌复合体I膜域的晶体结构,包括六个子单元和55个跨膜螺旋.
- 在L,M和N子单元中发现了一种新型的反载体状折叠,其中包括五个跨膜螺旋的两个倒置的,面对背的重复.
- 揭示了一条涉及极性残留网络的质子转移通路,其中 lysines 作为主要质子元素,以及在 N,K,J,A 接口的第四通道.
- 表明质子转位涉及六个对称结构元素的协调形状变化.
结论:
- 该结构为复合体I的膜域提供了前所未有的洞察力.
- 新的折叠和独特的质子转移机制涉及 lysines 挑战以前的假设.
- 这项工作为了解I复合体在能源生产和疾病发病过程中的功能奠定了基础.
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