• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >Structural basis for the network of functional cooperativities in cytochrome c(3) from Desulfovibrio gigas: solution structures of the oxidised and reduced states.
【24h】

Structural basis for the network of functional cooperativities in cytochrome c(3) from Desulfovibrio gigas: solution structures of the oxidised and reduced states.

机译：从脱硫弧菌细胞色素c（3）中的功能性合作网络的结构基础：氧化和还原态的溶液结构。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Cytochrome c(3) is a 14 kDa tetrahaem protein that plays a central role in the bioenergetic metabolism of Desulfovibrio spp. This involves an energy transduction mechanism made possible by a complex network of functional cooperativities between redox and redox/protolytic centres (the redox-Bohr effect), which enables cytochrome c(3) to work as a proton activator. The three-dimensional structures of the oxidised and reduced Desulfovibrio gigas cytochrome c(3) in solution were solved using 2D (1)H-NMR data. The reduced protein structures were calculated using INDYANA, an extended version of DYANA that allows automatic calibration of NOE data. The oxidised protein structure, which includes four paramagnetic centres, was solved using the program PARADYANA, which also includes the structural paramagnetic parameters. In this case, initial structures were used to correct the upper and lower volume restraints for paramagnetic leakage, and angle restraints derived from (13)C Fermi contact shifts of haem moiety substituents were used for the axial histidine ligands. Despite the reduction of the NOE intensities by paramagnetic relaxation, the final family of structures is of similar precision and accuracy to that obtained for the reduced form. Comparison of the two structures shows that, although the global folds of the two families of structures are similar, significant localised differences occur upon change of redox state, some of which could not be detected by comparison with the X-ray structure of the oxidised state: (1) there is a redox-linked concerted rearrangement of Lys80 and Lys90 that results in the stabilisation of haem moieties II and III when both molecules are oxidised or both are reduced, in agreement with the previously measured positive redox cooperativity between these two haem moieties. This cooperativity regulates electron transfer, enabling a two-electron step adapted to the function of cytochromes c(3) as the coupling partner of hydrogenase; and (2) the movement of haem I propionate 13 towards the interior of the protein upon reduction explains the positive redox-Bohr effect, establishing the structural basis for the redox-linked proton activation mechanism necessary for energy conservation, driving ATP synthesis. Copyright 2000 Academic Press.
机译：细胞色素c（3）是一种14 kDa的tetrahaem蛋白，在Desulfovibrio spp的生物能代谢中起核心作用。这涉及到由氧化还原和氧化还原/蛋白水解中心（氧化还原-玻尔效应）之间的功能性协作的复杂网络使能量转导机制成为可能，这使细胞色素c（3）可以用作质子活化剂。使用二维（1）H-NMR数据解决了溶液中氧化和还原的吉氏脱硫弧菌细胞色素c（3）的三维结构。减少的蛋白质结构使用INDANA的扩展版本INDYANA进行计算，该模型可以自动校准NOE数据。使用程序PARADYANA解决了包含四个顺磁中心的氧化蛋白结构，该程序还包括结构顺磁参数。在这种情况下，使用初始结构校正顺磁泄漏的上，下体积约束，将血红素部分取代基的（13）C费米接触位移衍生的角度约束用于轴向组氨酸配体。尽管顺磁弛豫降低了NOE强度，但最终的结构族具有与还原形式相似的精度和精确度。两种结构的比较表明，尽管两个结构族的整体折叠相似，但是在氧化还原状态改变时会出现明显的局部差异，其中一些与氧化态的X射线结构相比无法检测到：（1）Lys80和Lys90存在氧化还原相关的一致重排，当两个分子都被氧化或同时被还原时，可使血红素II和III稳定，这与先前测得的这两个血红素的正氧化还原协同作用是一致的部分。这种协同作用调节电子转移，使两个电子步骤适应于作为氢化酶偶联伴侣的细胞色素c（3）的功能。 （2）还原时血红素丙酸血红素I 13向蛋白质内部的运动解释了正的氧化还原-玻尔效应，为节约能量，驱动ATP合成所必需的氧化还原连接的质子活化机制奠定了结构基础。版权所有2000学术出版社。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号