title: An RNA pocket for an aliphatic hydrophobe.
abstract: We have isolated an RNA with specific affinity for the L-valine side chain, using selection-amplification. The active RNA secondary structure, identified by repeated selection, is a highly conserved asymmetric (4:10) internal loop adjacent to required G-U pairs. The binding free-energy per methylene is up to 1.5 kcal mol-1, and very dependent on group position. Amino acid binding is L-stereoselective and distinguishes aliphatic sidechains by size and, given the same total size, by configuration. Though aliphatic-RNA interactions have frequently been neglected, their avidity and specificity seem sufficient for a biological role.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder 80309-0347, USA.
authors.forename: I
authors.initials: I
authors.lastname: Majerfeld
authors.forename: M
authors.initials: M
authors.lastname: Yarus
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002846:Chromatography, Affinity; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry* / Q000378:metabolism*; D012641:Selection, Genetic; D013237:Stereoisomerism; D013379:Substrate Specificity; D014633:Valine / Q000737:chemistry / Q000378:metabolism
chemical_list: D000596:Amino Acids; D012313:RNA; D014633:Valine; D008274:Magnesium