Aminoacyl-tRNA Synthetases, the Genetic Code, and the Evolutionary Process

摘要: The aminoacyl-tRNA synthetases (AARSs) and their relationship to the genetic code are examined from evolutionary perspective. Despite a loose correlation between codon assignments AARS relationships, is far too highly structured have been ordered merely through wanderings of these enzymes. Nevertheless, AARSs very informative about process. Examination phylogenetic trees for each reveals following. (i) Their relationships mostly conform established organismal phylogeny: strong distinction exists bacterial- archaeal-type AARSs. (ii) Although profiles individual might be expected similar in general respects, they not. It argued that differences reflect stages process when taxonomic distributions became fixed, not nature (iii) Horizontal transfer genes Bacteria Archaea asymmetric: archaeal more prevalent than reverse, which seen only “gemini group.” (iv) most far-ranging transfers tended occur distant past, before or during formation primary domains. These findings also used refine theory at stage represented by root universal tree, cells were primitive modern counterparts thus exchanged material less restricted ways, effect evolving communal sense.