Altamura N, Capitanio N, Bonnefoy N, Papa S, Dujardin G
Centro di Studio sui Mitocondri e Metabolismo Energetico, CNR, Bari, Italy.
FEBS Lett. 1996 Mar 11;382(1-2):111-5. doi: 10.1016/0014-5793(96)00165-2.
The nuclear gene OXA1 was first isolated in Saccharomyces cerevisiae and found to be required at a post-translational step in cytochrome c oxidase biogenesis, probably at the level of assembly. Mutations in OXA1 lead to a complete respiratory deficiency. The protein Oxa1p is conserved through evolution and a human homolog has been isolated by functional complementation of a yeast oxa1- mutant. In order to further our understanding of the role of Oxa1p, we have constructed two yeast strains in which the OXA1 open reading frame was almost totally deleted. Cytochrome spectra and enzymatic activity measurements show the absence of heme aa3 and of a cytochrome c oxido-reductase activity and dramatic decrease of the oligomycin sensitive ATPase activity. Analysis of the respiratory complexes in non-denaturing gels reveals that Oxa1p is necessary for the correct assembly of the cytochrome c oxidase and the ATP synthase complex.
核基因OXA1最初是在酿酒酵母中分离得到的，发现它在细胞色素c氧化酶生物合成的翻译后步骤中是必需的，可能在组装水平。OXA1中的突变导致完全的呼吸缺陷。Oxa1p蛋白在进化过程中是保守的，并且通过酵母oxa1-突变体的功能互补分离出了人类同源物。为了进一步了解Oxa1p的作用，我们构建了两个酵母菌株，其中OXA1开放阅读框几乎完全缺失。细胞色素光谱和酶活性测量表明，不存在血红素aa3和细胞色素c氧化还原酶活性，并且寡霉素敏感的ATP酶活性显著降低。在非变性凝胶中对呼吸复合物的分析表明，Oxa1p对于细胞色素c氧化酶和ATP合酶复合物的正确组装是必需的。
