Prokaryotic orthologues of mitochondrial alternative oxidase and plastid terminal oxidase
Prokaryotic orthologues of mitochondrial alternative oxidase and plastid terminal oxidase
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线粒体替代氧化酶和质体末端氧化酶的原核直系同源物
DOI：
10.1023/b:plan.0000023669.79465.d2
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发表时间：
2003
影响因子：
5.1
通讯作者：
G. C. Vanlerberghe
中科院分区：
文献类型：
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作者：
A. McDonald;S. Amirsadeghi;G. C. Vanlerberghe
线粒体交替氧化酶（AOX）和质体末端氧化酶（PTOX）是两个相似的成员膜结合的二铁羧酸类蛋白质。AOX是存在于所有高等植物以及一些藻类、真菌和原生生物中的泛醇氧化酶。它可以通过呼吸电子传递链抑制活性氧的产生。PTOX是植物和一些藻类中的质体醌醇氧化酶。它是类胡萝卜素生物合成所必需的，并可能代表氯呼吸中难以捉摸的氧化酶。最近，AOX和PTOX蛋白的原核直向同源物已经出现在序列数据库中。这些包括存在于四种不同蓝藻中的PTOX直向同源物以及α-变形菌中的AOX直向同源物。我们利用PCR、RT-PCR和北方分析证实了变异鱼腥藻PCC 7120中PTOX基因的存在和表达。新发现的原核和真核AOX和PTOX蛋白的广泛同源性支持了这样的想法，即AOX和PTOX代表两组不同的蛋白质，它们在引起真核细胞器的内共生事件之前分化。使用多序列比对，我们确定了所有AOX和PTOX蛋白中保守的残基。我们还提供了一个方案，容易区分PTOX AOX蛋白的基础上保守的铁结合残基周围的基序中的氨基酸序列的差异。鉴于存在的蓝藻中的PTOX，我们建议，这个缩写现在代表质体醌醇末端氧化酶。我们的研究结果对这些原核生物的光合和呼吸代谢，以及真核生物AOX和PTOX蛋白的起源和进化具有一定的意义。
The mitochondrial alternative oxidase (AOX) and the plastid terminal oxidase (PTOX) are two similar members of the membrane-bound diiron carboxylate group of proteins. AOX is a ubiquinol oxidase present in all higher plants, as well as some algae, fungi, and protists. It may serve to dampen reactive oxygen species generation by the respiratory electron transport chain. PTOX is a plastoquinol oxidase in plants and some algae. It is required in carotenoid biosynthesis and may represent the elusive oxidase in chlororespiration. Recently, prokaryotic orthologues of both AOX and PTOX proteins have appeared in sequence databases. These include PTOX orthologues present in four different cyanobacteria as well as an AOX orthologue in an α-proteobacterium. We used PCR, RT-PCR and northern analyses to confirm the presence and expression of the PTOX gene in Anabaena variabilis PCC 7120. An extensive phylogeny of newly found prokaryotic and eukaryotic AOX and PTOX proteins supports the idea that AOX and PTOX represent two distinct groups of proteins that diverged prior to the endosymbiotic events that gave rise to the eukaryotic organelles. Using multiple sequence alignment, we identified residues conserved in all AOX and PTOX proteins. We also provide a scheme to readily distinguish PTOX from AOX proteins based upon differences in amino acid sequence in motifs around the conserved iron-binding residues. Given the presence of PTOX in cyanobacteria, we suggest that this acronym now stand for plastoquinol terminal oxidase. Our results have implications for the photosynthetic and respiratory metabolism of these prokaryotes, as well as for the origin and evolution of eukaryotic AOX and PTOX proteins.
影响因子：
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作者：
G. Pfeifer;A. Riggs
通讯作者：
G. Pfeifer;A. Riggs