Atteia Ariane, van Lis Robert, van Hellemond Jaap J, Tielens Aloysius G M, Martin William, Henze Katrin
Institute of Botany III, Heinrich Heine University of Düsseldorf, Universitätsstrasse 1, D-40225 Düsseldorf, Germany.
Gene. 2004 Apr 14;330:143-8. doi: 10.1016/j.gene.2004.01.015.
The alternative oxidase is a ubiquinol oxidase that has been found to date in the mitochondrial respiratory chain of plants, some fungi and protists. Because of its sparse distribution among eukaryotic lineages and because of its diversity in regulatory mechanisms, the origin of AOX has been a mystery, particularly since no prokaryotic homologues have previously been identified. Here we report the identification of a gene encoding a clear homologue of the mitochondrial alternative oxidase in an alpha-proteobacterium, and the identification of three cyanobacterial genes that encode clear homologues of the plastid-specific alternative oxidase of plants and algae. These findings suggest that the eukaryotic nuclear genes for the alternative oxidases of mitochondria and chloroplasts were acquired via endosymbiotic gene transfer from the eubacterial ancestors of these two organelles, respectively.
交替氧化酶是一种泛醇氧化酶，迄今为止已在植物、一些真菌和原生生物的线粒体呼吸链中发现。由于其在真核生物谱系中的分布稀少，以及其调控机制的多样性，交替氧化酶的起源一直是个谜，特别是因为以前尚未鉴定出原核生物同源物。在这里，我们报告在一种α-变形杆菌中鉴定出一个编码线粒体交替氧化酶明确同源物的基因，以及在三种蓝细菌中鉴定出三个编码植物和藻类质体特异性交替氧化酶明确同源物的基因。这些发现表明，线粒体和叶绿体交替氧化酶的真核核基因分别是通过内共生基因转移从这两个细胞器的真细菌祖先那里获得的。
