Acceptor stem and anticodon RNA hairpin helix interactions with glutamine tRNA synthetase.
The class I glutamine (Gln) tRNA synthetase interacts with the anticodon and acceptor stem of glutamine tRNA. RNA hairpin helices were designed to probe acceptor stem and anticodon stem-loop contacts. A seven-base pair RNA microhelix derived from the acceptor stem of tRNA(Gln) was aminoacylated by Gln tRNA synthetase. Variants of the glutamine acceptor stem microhelix implicated the discriminator base as a major identity element for glutaminylation of the RNA helix. A second RNA microhelix representing the anticodon stem-loop competitively inhibited tRNA(Gln) changing. However, the anticodon stem-loop microhelix did not enhance aminoacylation of the acceptor stem microhelix. Thus, transduction of the anticodon identity signal may require covalent continuity of the tRNA chain to trigger efficient aminoacylation.
Wright
D J
DJ
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
Martinis
S A
SA
Jahn
M
M
Söll
D
D
Schimmel
P
P
D000215:Acylation; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000926:Anticodon / Q000737:chemistry / Q000378:metabolism*; D001482:Base Composition; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000201:enzymology; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012351:RNA, Transfer, Gln / Q000737:chemistry / Q000378:metabolism*
D000926:Anticodon; D012351:RNA, Transfer, Gln; D000604:Amino Acyl-tRNA Synthetases; C020659:glutaminyl-tRNA synthetase