title: Genetic code origins: tRNAs older than their synthetases?
abstract: We present a phylogenetic analysis to determine whether a given tRNA molecule was established in evolution before its cognate aminoacyl-tRNA synthetase. The earlier appearance of tRNA versus their metabolically related enzymes is a prediction of the RNA world theory, but the available synthetase and tRNA sequences previously had not allowed a formal comparison of their relative time of appearance. Using data recently obtained from the emerging genome projects, our analysis points to the extant forms of lysyl-tRNA synthetase being preceded in evolution by the establishment of the identity of lysine tRNA.
authors.affiliation: The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: L
authors.initials: L
authors.lastname: Ribas de Pouplana
authors.forename: R J
authors.initials: RJ
authors.lastname: Turner
authors.forename: B A
authors.initials: BA
authors.lastname: Steer
authors.forename: P
authors.initials: P
authors.lastname: Schimmel
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000235:genetics*; D001105:Archaea / Q000737:chemistry; D001419:Bacteria / Q000737:chemistry; D005075:Biological Evolution; D005057:Eukaryotic Cells / Q000737:chemistry; D005815:Genetic Code / Q000235:genetics*; D010802:Phylogeny; D012313:RNA / Q000737:chemistry / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics*; D012357:RNA, Transfer, Lys / Q000096:biosynthesis; D016415:Sequence Alignment
chemical_list: D012357:RNA, Transfer, Lys; D012313:RNA; D012343:RNA, Transfer; D000604:Amino Acyl-tRNA Synthetases