Association of transfer RNA acceptor identity with a helical irregularity.
The aminoacylation specificity ("acceptor identity") of transfer RNAs (tRNAs) has previously been associated with the position of particular nucleotides, as opposed to distinctive elements of three-dimensional structure. The contribution of a G.U wobble pair in the acceptor helix of tRNA(Ala) to acceptor identity was examined with synthetic amber suppressor tRNAs in Escherichia coli. The acceptor identity was not affected by replacing the G.U wobble pair in tRNA(Ala) with a G.A, C.A, or U.U wobble pair. Furthermore, a tRNA(Ala) acceptor identity was conferred on tRNA(Lys) when the same site in the acceptor helix was replaced with any of several wobble pairs. Additional data with tRNA(Ala) show that a substantial acceptor identity was retained when the G.U wobble pair was translocated to another site in the acceptor helix. These results suggest that the G.U wobble pair induces an irregularity in the acceptor helix of tRNA(Ala) to match a complementary structure in the aminoacylating enzyme.
McClain
W H
WH
Department of Bacteriology, University of Wisconsin, Madison 53706.
Chen
Y M
YM
Foss
K
K
Schneider
J
J
D001482:Base Composition; D004926:Escherichia coli / Q000235:genetics*; D009154:Mutation; D009690:Nucleic Acid Conformation; D012329:RNA, Bacterial / Q000378:metabolism*; D012344:RNA, Transfer, Ala / Q000378:metabolism*; D012345:RNA, Transfer, Amino Acid-Specific / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013489:Suppression, Genetic
D012329:RNA, Bacterial; D012344:RNA, Transfer, Ala; D012345:RNA, Transfer, Amino Acid-Specific