Zúñiga Manuel, Pérez Gaspar, González-Candelas Fernando
Instituto de Agroquímica y Tecnología de Alimentos-CSIC, Valencia, Spain.
Mol Phylogenet Evol. 2002 Dec;25(3):429-44. doi: 10.1016/s1055-7903(02)00277-4.
We have analyzed the evolution of the three genes encoding structural enzymes of the arginine deiminase (ADI) pathway, arginine deiminase (ADI), ornithine transcarbamoylase (OTC), and carbamate kinase (CK) in a wide range of organisms, including Archaea, Bacteria, and Eukarya. This catabolic route was probably present in the last common ancestor to all the domains of life. The results obtained indicate that these genes have undergone a complex evolutionary history, including horizontal transfer events, duplications, and losses. Therefore, these genes are not adequate to infer organismal relationships at deep branching levels, but they provide an insight into how catabolic genes evolved and were assembled into metabolic pathways. Our results suggest that the three genes evolved independently and were later assembled into a single cluster with functional interdependence, thus, providing support for the gene recruitment hypothesis. Furthermore, the molecular phylogenetic analysis of OTC suggests a new classification of these genes into three subfamilies.
我们分析了编码精氨酸脱亚氨酶（ADI）途径结构酶的三个基因，即精氨酸脱亚氨酶（ADI）、鸟氨酸转氨甲酰酶（OTC）和氨基甲酸激酶（CK）在包括古细菌、细菌和真核生物在内的广泛生物体中的进化情况。这条分解代谢途径可能存在于所有生命域的最后一个共同祖先中。获得的结果表明，这些基因经历了复杂的进化历史，包括水平转移事件、复制和丢失。因此，这些基因不足以推断深层次分支水平上的生物关系，但它们为分解代谢基因如何进化并组装成代谢途径提供了见解。我们的结果表明，这三个基因独立进化，后来组装成一个具有功能相互依赖性的单一簇，从而为基因招募假说提供了支持。此外，OTC的分子系统发育分析表明，这些基因可分为三个亚家族的新分类。
