title: Anticodon G recognition by tRNA synthetases mimics the tRNA core.
abstract: Ancient mechanisms for nucleotide base recognition in the RNA world are candidates for mimicking by early proteins like tRNA synthetases. In the core of the tRNA, conserved G22 interacts with two internal bases in a complex further stabilized by stacking interactions. This particular tRNA format for G recognition is shown here to be adapted by nine different and even nonhomologous anticodon binding domains (ABDs) of tRNA synthetases, in which amino acid side chains mimic all of the tRNA G22 base interactions. We offer the possibility that mimicking this RNA-based mechanism for guanine recognition is perhaps one of the selective pressures for choosing amino acids for the genetic code.
authors.affiliation: Department of Molecular Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Liron
authors.initials: L
authors.lastname: Klipcan
authors.forename: Mark
authors.initials: M
authors.lastname: Safro
authors.forename: Paul
authors.initials: P
authors.lastname: Schimmel
mesh_terms: D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000926:Anticodon; D020029:Base Pairing; D001483:Base Sequence; D001665:Binding Sites; D005815:Genetic Code; D006801:Humans; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011487:Protein Conformation; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D000926:Anticodon; D012343:RNA, Transfer; D000604:Amino Acyl-tRNA Synthetases