title: Tertiary structure in E. coli tRNA Arg and tRNA Val.
abstract: 300 MHz proton NMR has been used to demonstrate that both Escherichia coli tRNA Arg and tRNA(1) Val have a tertiary structure base pair between 4-thiouridine (s-4U) at position 8 and A at position 14. Formation of this s-4U(8)-A(14) base pair leads to a very low field (14.8 ppm) resonance in the spectra of both molecules. When s-4U is converted to U the 14.8 resonance is replaced by a new resonance which appears at 14.3 ppm. The presence of the tertiary structure s-4U(8)-A(14) base pair greatly constrains the folding of these tRNAs in solution.
mesh_terms: D001120:Arginine; D001483:Base Sequence; D004926:Escherichia coli / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial; D012343:RNA, Transfer; D013891:Thiouridine; D014633:Valine
chemical_list: D012329:RNA, Bacterial; D013891:Thiouridine; D012343:RNA, Transfer; D001120:Arginine; D014633:Valine