title: Interactions of Escherichia coli SO-187 tRNA(IVal) with Bacillus stearothermophilus valine-tRNA synthetase studied by 13C-NMR.
abstract: Uracil isotopically labelled with 13C at C4 and C5 has been incorporated into nucleic acids of the Escherichia coli uracil auxotroph, SO-187. [4,5-13C]uracil-labeled tRNA(IVal) was isolated and purified. 13C longitudinal relaxation times measured at 67.8 MHz demonstrated that the C5 dipole caused a 20-50% increase in the C4 relaxation. Interactions of this tRNA with valine-tRNA synthetase (VTS) purified from Bacillus stearothermophilus were established by 13C-NMR. Specific spectral changes were seen at 4-thiouridine, ribothymidine and pseudouridine of the 'bend' in the three-dimensional structure, and particularly at the uridine-5-oxyacetic acid in the wobble position of the anticodon. Thus, the protein seems to be in contact along the entire tRNA molecule, including the anticodon loop.
authors.affiliation: Department of Medicinal Chemistry, University of Utah, Salt Lake City 84112.
authors.forename: M P
authors.initials: MP
authors.lastname: Schweizer
authors.forename: J I
authors.initials: JI
authors.lastname: Olsen
authors.forename: J A
authors.initials: JA
authors.lastname: Stolk
authors.forename: Y C
authors.initials: YC
authors.lastname: Lee
authors.forename: P M
authors.initials: PM
authors.lastname: Reeves
authors.forename: C
authors.initials: C
authors.lastname: Perry
authors.forename: N
authors.initials: N
authors.lastname: De
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D001407:Bacillus / Q000201:enzymology*; D004926:Escherichia coli / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D012345:RNA, Transfer, Amino Acid-Specific / Q000378:metabolism*; D012366:RNA, Transfer, Val / Q000378:metabolism*; D014498:Uracil / Q000378:metabolism*; D014637:Valine-tRNA Ligase / Q000378:metabolism*
chemical_list: D012345:RNA, Transfer, Amino Acid-Specific; D012366:RNA, Transfer, Val; D014498:Uracil; D000604:Amino Acyl-tRNA Synthetases; D014637:Valine-tRNA Ligase