title: Trans-acting RNA inhibits tRNA suppressor activity in vivo.
abstract: We constructed two aptamers, each of which contains a 7-nt-long loop complementary to the anticodon loop of a suppressor tRNA. One of these aptamers can form a stable bimolecular complex with the suppressor tRNA in vitro and protects the 7 nt in the suppressor's anticodon loop from RNase S1. An Escherichia coli strain, carrying an amber mutation in the lac Z gene, produces beta-galactosidase only if the suppressor is present; the aptamer's coexpression in the cell inhibits the activity of the suppressor tRNA. Moreover, in E. coli extract, the aptamer partially inhibits the read-through of the stop codon on the part of the suppressor tRNA. These results point to a novel strategy that need not be limited to the suppressor tRNA. By constructing appropriate inducible aptamers, it may well be possible to effectively control translation in vivo.
authors.affiliation: Istituto di Biologia Cellulare, Consiglio Nazionale delle Ricerche, Monterotondo Scalo, RM, Italy.
authors.forename: Domenica Gandini
authors.initials: DG
authors.lastname: Attardi
authors.forename: Glauco P
authors.initials: GP
authors.lastname: Tocchini-Valentini
mesh_terms: D000926:Anticodon / Q000235:genetics; D001483:Base Sequence; D018388:Codon, Terminator / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007763:Lac Operon; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D010443:Peptide Chain Termination, Translational; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013489:Suppression, Genetic; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000926:Anticodon; D018388:Codon, Terminator; D012329:RNA, Bacterial; D012343:RNA, Transfer; D001616:beta-Galactosidase