title: RNA-catalyzed amino acid activation.
abstract: We have selected RNAs that perform a new reaction that chemically activates amino acids, paralleling mixed phosphate anhydride synthesis by protein aminoacyl-transfer RNA synthetases. Care with recovery of the unstable reaction product was apparently essential to this selection. The best characterized RNA, KK13, requires only Ca2+ for reaction and is optimally active at low pH with KM = 50 mM and kcat = 1.1 min(-1) for activation of leucine. In conjunction with previous RNA-catalyzed aminoacyl-RNA synthesis, peptide bond formation, and RNA-based coding, these amino acid-activating RNAs complete an experimental demonstration that the four fundamental reactions of protein biosynthesis can be RNA-mediated. The appearance of translation in an RNA world is therefore supported.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309-0347, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Kumar
authors.forename: M
authors.initials: M
authors.lastname: Yarus
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D049148:Aminoacylation; D001483:Base Sequence; D002264:Carboxylic Acids / Q000737:chemistry; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D011756:Diphosphates / Q000737:chemistry; D006157:Guanosine Monophosphate / Q000737:chemistry; D006160:Guanosine Triphosphate / Q000737:chemistry; D007930:Leucine / Q000737:chemistry; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012315:RNA Caps / Q000737:chemistry; D016337:RNA, Catalytic / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D002264:Carboxylic Acids; D011756:Diphosphates; D012315:RNA Caps; D016337:RNA, Catalytic; D006157:Guanosine Monophosphate; D006160:Guanosine Triphosphate; D007930:Leucine