title: A modified uridine in the anticodon of E. coli tRNA I Tyr su + oc.
abstract: The anticodon of an ochre-suppressing derivative of E. coli tRNA I Tyr, previously identified as UUA, can contain a modified uridine (U+) in the first position. The novel modified nucleotide has been identified by two-dimensional thin layer chromatography following RNase T2 digestion of anticodon-containing fragments. Up+ is found in less than stoichiometric molar yields in preparations of tRNA I Tyr su + oc. The electrophoretic mobility of Up+ is the same as Up at pH 3.5 and pH 7.5. U+ probably does not contain sulfur since it cannot be labeled with 35S in vivo incorporation experiments.
mesh_terms: D000926:Anticodon; D001483:Base Sequence; D002855:Chromatography, Thin Layer; D004926:Escherichia coli / Q000032:analysis; D012343:RNA, Transfer; D012260:Ribonucleases; D012265:Ribonucleotides / Q000032:analysis; D014529:Uridine
chemical_list: D000926:Anticodon; D012265:Ribonucleotides; D012343:RNA, Transfer; D012260:Ribonucleases; D014529:Uridine