title: Photolabile and paramagnetic derivatives of the nucleoside X and of Escherichia coli tRNAPhe.
abstract: The synthesis of N3-[3-L-(5-azido-2-nitrobenzamido)-3-carboxypropyl]uridine (4b) and N3-[3-carboxy-3-L-(2,2,5,5-tetramethyl-3-pyrroline-3-carbonylamino)propyl]uridine Npyr-oxyl (4c) starting from the nucleoside X (4a) and the appropriate N-hydroxysuccinimide ester 1 or 2 is described. After acylation of tRNAPhe from E. coli (5a) with 1 or 2, the photolabile tRNAPhe derivative 5b and the paramagnetic tRNAPhe derivative 5c could be isolated. The position of modification in the polynucleotide chain was elucidated by comparison of the ribonuclease II/alkaline phosphatase digestion products of the substituted and unsubstituted tRNAPhe samples, and was identified as being exclusively the amino group of the nucleoside X in position 47 of E. coli tRNAPhe.
mesh_terms: D000613:Aminobutyrates / Q000032:analysis; D001483:Base Sequence; D004578:Electron Spin Resonance Spectroscopy; D004926:Escherichia coli / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D010649:Phenylalanine; D010782:Photolysis; D012343:RNA, Transfer; D013056:Spectrophotometry, Ultraviolet; D014529:Uridine / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D000613:Aminobutyrates; D010649:Phenylalanine; D012343:RNA, Transfer; D014529:Uridine