title: Ability of modified forms of phenylalanine tRNA to stimulate guanosine pentaphosphate synthesis by the stringent factor-ribosome complex of E. coli.
abstract: tRNA(Phe) of E. coli, modified at its 4-thiouridine ((4)Srd) and 3-(3-amino-3-carboxypropyl)uridine (nbt(3)Urd) residues, was tested for its ability to induce (p)ppGpp synthesis. The (4)Srd residue was derivatized with the p-azido-phenacyl group, cross-linked to Cyd(13), and the borohydride reduction product of the cross-link was prepared. The nbt(3)Urd residue was derivatized with the N-(4-azido-2-nitrophenyl)glycyl group. None of these derivatives had more than a minor effect on the affinity of the tRNA for the stringent factor-ribosome complex, and no effect at all on the maximum velocity of (p)ppGpp synthesis, either at 2 or 82 mM NH(4)Cl. These two regions of the tRNA which are on opposite faces of the tRNA molecule do not appear to be structurally important for recognition by the stringent factor-ribosome complex. They may provide useful sites, therefore, for the introduction of photoaffinity or fluorescent probes with which to study tRNA-stringent factor recognition.
mesh_terms: D000643:Ammonium Chloride; D001426:Bacterial Proteins / Q000378:metabolism*; D001665:Binding Sites; D004926:Escherichia coli / Q000378:metabolism*; D006150:Guanine Nucleotides / Q000096:biosynthesis*; D006159:Guanosine Tetraphosphate / Q000096:biosynthesis*; D009994:Osmolar Concentration; D010649:Phenylalanine; D012343:RNA, Transfer / Q000031:analogs & derivatives / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D013891:Thiouridine; D014529:Uridine / Q000031:analogs & derivatives
chemical_list: D001426:Bacterial Proteins; D006150:Guanine Nucleotides; D012269:Ribosomal Proteins; D000643:Ammonium Chloride; D013891:Thiouridine; D006159:Guanosine Tetraphosphate; D010649:Phenylalanine; C006514:3-(3-amino-3-carboxypropyl)uridine; D012343:RNA, Transfer; D014529:Uridine