Multi-step assembly pathway of the cbb3-type cytochrome c oxidase complex
Multi-step assembly pathway of the cbb3-type cytochrome c oxidase complex
复制标题
DOI：
10.1016/j.jmb.2005.11.039
复制
发表时间：
2006-02-03
影响因子：
5.6
通讯作者：
Koch, HG
中科院分区：
文献类型：
--
作者：
Kulajta, C;Thumfart, JO;Koch, HG
cbb（3）型细胞色素c氧化酶是血红素-铜氧化酶超家族的成员，参与致病性和非致病性变形菌的微氧呼吸。这些由ccoNOQP操纵子编码的多亚基酶的生物发生依赖于ccoGHIS基因产物，这些产物被认为是cbb（3）型细胞色素c氧化酶的辅因子插入和成熟所特别需要的。在这里，组装的cbb（3）型细胞色素c氧化酶从兼性光合模式生物Rhodobacter capsulatus的研究使用蓝色聚丙烯酰胺凝胶电泳。该过程涉及稳定但无活性的210 kDa的形成。由亚基CcoNOQ和组装蛋白CcoH和CcoS组成的亚复合物。通过募集单体CcoP，该亚复合物被转化为活性230 kDa CcoNOQP复合物。这些复合物的形成和单体CcoP的稳定性在缺失ccoGHIS后急剧受损。在ccoI缺失菌株中，230 kDa的复合物是不存在的，虽然单体CcoP仍然是可检测的。与此相反，无论是复合物，也没有单体CcoP中发现的ccoH缺失菌株。在不存在CcoS的情况下，230 kDa。复合体已组装。然而，它没有表现出酶活性，这表明CcoS可能参与了生物合成的后期步骤。基于这些数据，我们提出CcoN，CcoO和CcoQ组装成一个无活性的210 kDa的子复合物，这是通过其与CcoH和CcoS的相互作用稳定。CcoP的结合，以及可能随后的CcoH和CcoS的解离，然后产生活性230 kDa复合物。血红素辅因子插入c型细胞色素CcoP和CcoO先于亚复合物形成，而辅因子插入CcoN可能发生在cbb（3）型细胞色素c氧化酶组装期间210 kDa亚复合物形成之前或之后。(c)2005爱思唯尔有限公司保留所有权利。
The cbb(3)-type cytochrome c oxidases as members of the heme-copper oxidase superfamily are involved in microaerobic respiration in both pathogenic and non-pathogenic proteobacteria. The biogenesis of these multisubunit enzymes, encoded by the ccoNOQP operon, depends on the ccoGHIS gene products, which are proposed to be specifically required for co-factor insertion and maturation of cbb(3)-type cytochrome c oxidases. Here, the assembly of the cbb(3)-type cytochrome c oxidase from the facultative photosynthetic model organism Rhodobacter capsulatus was investigated using blue-native polyacrylamide gel electrophoresis. This process involves the formation of a stable but inactive 210 kDa. sub-complex consisting of the subunits CcoNOQ and the assembly proteins CcoH and CcoS. By recruiting monomeric CcoP, this sub-complex is converted into an active 230 kDa CcoNOQP complex. Formation of these complexes and the stability of the monomeric CcoP are impaired drastically upon deletion of ccoGHIS. In a ccoI deletion strain, the 230 kDa complex was absent, although monomeric CcoP was still detectable. In contrast, neither of the complexes nor the monomeric CcoP was found in a ccoH deletion strain. In the absence of CcoS, the 230 kDa. complex was assembled. However, it exhibited no enzymatic activity, suggesting that CcoS might be involved in a late step of biogenesis. Based on these data, we propose that CcoN, CcoO and CcoQ assemble first into an inactive 210 kDa sub-complex, which is stabilized via its interactions with CcoH and CcoS. Binding of CcoP, and probably subsequent dissociation of CcoH and CcoS, then generates the active 230 kDa complex. The insertion of the heme cofactors into the c-type cytochromes CcoP and CcoO precedes sub-complex formation, while the cofactor insertion into CcoN could occur either before or after the 210 kDa sub-complex formation during the assembly of the cbb(3)-type cytochrome c oxidase. (c) 2005 Elsevier Ltd. All rights reserved.