title: The isolation from ribonucleic acid of substituted uridines containing alpha-aminobutyrate moieties derived from methionine.
abstract: The RNA of an established line of Chinese hamster cells growing in cell culture contains a small number of uridines substituted at the 3-position with a gamma-linked alpha-aminobutyrate residue. Structure has been ascertained by: (a) examination of incorporation of isotopic labels from precursors; (b) degradation with anhydrous hydrazine and comparison of the products with synthetic material or with hydrazinolysis products of known uridines; and (c) comparison of the unknowns as their hydantoin derivatives with the 5-beta-(bromoethyl)hydantoin alkylation products of uridine and of 1- and 3-methylpseudouridine. In this manner it is shown that 18-S RNA of ribosomes contains a single residue of a nucleoside which we tentatively identify as 1-methyl-3-gamma-(alpha-amino-alpha-carboxypropyl)pseudouridine per molecule. RNA isolated from the supernatant fraction, sedimenting at 4 S and co-electrophoresing with transfer RNA on polyacrylamide gels, contains several similar bases, one of which is identified as 3-gamma-(alpha-amino-alpha-carboxypropyl)uridine. Each of the above nucleosides derives its alpha-aminobutyrate residue from methionine.
authors.affiliation: Cellular and Molecular Radiobiology Group, Los Alamos Scientific Laboratory, University of California, Los Alamos, N.M. 87544, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Saponara
authors.forename: M D
authors.initials: MD
authors.lastname: Enger
mesh_terms: D000613:Aminobutyrates / Q000737:chemistry*; D000818:Animals; D016466:CHO Cells; D002499:Centrifugation, Density Gradient; D002854:Chromatography, Paper; D006224:Cricetinae; D003412:Cricetulus; D006830:Hydralazine; D006863:Hydrogen-Ion Concentration; D008715:Methionine / Q000737:chemistry*; D008956:Models, Chemical; D011560:Pseudouridine / Q000031:analogs & derivatives* / Q000737:chemistry; D012313:RNA / Q000737:chemistry*; D013053:Spectrophotometry; D014316:Tritium; D014529:Uridine / Q000031:analogs & derivatives / Q000302:isolation & purification*
chemical_list: D000613:Aminobutyrates; D014316:Tritium; C013608:1-methylpseudouridine; D011560:Pseudouridine; D006830:Hydralazine; D012313:RNA; C034686:3-methylpseudouridine; D008715:Methionine; D014529:Uridine