EVOLUTION OF CYTOCHROME-OXIDASE, AN ENZYME OLDER THAN ATMOSPHERIC OXYGEN
EVOLUTION OF CYTOCHROME-OXIDASE, AN ENZYME OLDER THAN ATMOSPHERIC OXYGEN
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DOI：
10.1002/j.1460-2075.1994.tb06541.x
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发表时间：
1994-06-01
期刊：
影响因子：
11.4
通讯作者：
HIGGINS, DG
中科院分区：
文献类型：
--
作者：
CASTRESANA, J;LUBBEN, M;HIGGINS, DG
细胞色素氧化酶是有氧代谢的关键酶。所有记录的真细菌（域细菌）和古细菌（古细菌）的亚基1和2的这种蛋白质复合物的序列已被用于全面的进化分析。系统发育树揭示了基因复制的几个过程。其中一些是古老的，发生在细菌和细菌的共同祖先中，而另一些则发生在细菌的特定品系中。我们表明，真细菌醌醇氧化酶是来自细胞色素c氧化酶在革兰氏阳性菌和古细菌醌醇氧化酶有一个独立的起源。大量的证据表明，变形菌门（紫色细菌）通过从革兰氏阳性菌的横向基因转移获得了醌醇氧化酶。有氧代谢在有氧光合作用后的进化中出现了几次的流行假说，不支持两个方面的分子数据。首先，细胞色素氧化酶存在于古细菌和细菌的共同祖先中，而产氧光合作用出现在细菌中。其次，固氮细菌中现存的细胞色素氧化酶表明，有氧代谢在氧气水平非常低的环境中是可能的，例如豆科植物的根瘤。因此，我们提出，有氧代谢与细胞色素氧化酶的生物体具有单系和古老的起源，在真细菌产氧光合生物的出现。
Cytochrome oxidase is a key enzyme in aerobic metabolism. All the recorded eubacterial (domain Bacteria) and archaebacterial (Archaea) sequences of subunits 1 and 2 of this protein complex have been used for a comprehensive evolutionary analysis. The phylogenetic trees reveal several processes of gene duplication. Some of these are ancient, having occurred in the common ancestor of Bacteria and Archaea, whereas others have occurred in specific lines of Bacteria. We show that eubacterial quinol oxidase was derived from cytochrome c oxidase in Gram-positive bacteria and that archaebacterial quinol oxidase has an independent origin. A considerable amount of evidence suggests that Proteobacteria (Purple bacteria) acquired quinol oxidase through a lateral gene transfer from Gram-positive bacteria. The prevalent hypothesis that aerobic metabolism arose several times in evolution after oxygenic photosynthesis, is not sustained by two aspects of the molecular data. First, cytochrome oxidase was present in the common ancestor of Archaea and Bacteria whereas oxygenic photosynthesis appeared in Bacteria. Second, an extant cytochrome oxidase in nitrogen-fixing bacteria shows that aerobic metabolism is possible in an environment with a very low level of oxygen, such as the root nodules of leguminous plants. Therefore, we propose that aerobic metabolism in organisms with cytochrome oxidase has a monophyletic and ancient origin, prior to the appearance of eubacterial oxygenic photosynthetic organisms.