Abstract The respiratory pathway of mitochondria is composed of four electron transfer complexes and the ATP synthase. In this article, we review evidence from studies of Saccharomyces cerevisiae that both ATP synthase and cytochrome oxidase (COX) are assembled from independent modules that correspond to structurally and functionally identifiable components of each complex. Biogenesis of the respiratory chain requires a coordinate and balanced expression of gene products that become partner subunits of the same complex, but are encoded in the two physically separated genomes. Current evidence indicates that synthesis of two key mitochondrial encoded subunits of ATP synthase is regulated by the F1 module. Expression of COX1 that codes for a subunit of the COX catalytic core is also regulated by a mechanism that restricts synthesis of this subunit to the availability of a nuclear-encoded translational activator. The respiratory chain must maintain a fixed stoichiometry of the component enzyme complexes during cell growth. We propose that high-molecular-weight complexes composed of Cox6, a subunit of COX, and of the Atp9 subunit of ATP synthase play a key role in establishing the ratio of the two complexes during their assembly.

中文翻译：

---

酵母线粒体ATP合酶和细胞色素氧化酶的模块化组装

摘要 线粒体的呼吸通路由四种电子传递复合物和ATP合酶组成。在本文中，我们回顾了来自酿酒酵母研究的证据，即 ATP 合酶和细胞色素氧化酶 (COX) 均由独立模块组装而成，这些模块对应于每个复合物的结构和功能可识别成分。呼吸链的生物发生需要基因产物的协调和平衡表达，这些基因产物成为同一复合体的伙伴亚基，但在两个物理分离的基因组中编码。目前的证据表明，ATP 合酶的两个关键线粒体编码亚基的合成受 F1 模块的调控。编码 COX 催化核心亚基的 COX1 的表达也受到一种机制的调节，该机制将该亚基的合成限制为核编码翻译激活剂的可用性。在细胞生长过程中，呼吸链必须保持组成酶复合物的固定化学计量。我们建议由 Cox6、COX 亚基和 ATP 合酶的 Atp9 亚基组成的高分子量复合物在组装过程中建立两种复合物的比例方面起着关键作用。