Footprinting the sites of interaction of antibiotics with catalytic group I intron RNA.
Aminoglycoside inhibitors of translation have been shown previously to inhibit in vitro self-splicing by group I introns. Chemical probing of the phage T4-derived sunY intron shows that neomycin, streptomycin, and related antibiotics protected the N-7 position of G96, a universally conserved guanine in the binding site for the guanosine cofactor in the splicing reaction. The antibiotics also disrupted structural contacts that have been proposed to bring the 5' cleavage site of the intron into proximity to the catalytic core. In contrast, the strictly competitive inhibitors deoxyguanosine and arginine protected only the N-7 position of G96. Parallels between these results and previously observed protection of 16S ribosomal RNA by aminoglycosides raise the possibility that group I intron splicing and transfer RNA selection by ribosomes involve similar RNA structural motifs.
Sinsheimer Laboratories, University of California, Santa Cruz 95064.
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von Ahsen
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Noller
D000617:Aminoglycosides; D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D001483:Base Sequence; D001665:Binding Sites; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation / Q000187:drug effects; D012326:RNA Splicing / Q000187:drug effects; D016337:RNA, Catalytic / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D013768:Tetrahymena / Q000235:genetics
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D016337:RNA, Catalytic