Characterization of a 1,4-disubstituted 1,2,3-triazole binding to T box antiterminator RNA.
The T box riboswitch regulates the transcription of many bacterial genes by structurally responding to cognate non-aminoacylated (uncharged) tRNA. The riboswitch contains multiple conserved RNA elements including a key structural element, the antiterminator, which binds the tRNA acceptor end nucleotides. Previous studies identified a lead 1,4-disubstituted 1,2,3-triazole, GHB-7, that disrupted formation of a tRNA-antiterminator RNA model complex. The affinity and molecular interactions of GHB-7 binding to antiterminator model RNA were characterized as part of a comprehensive T box antiterminator RNA-targeted drug discovery project. In-line probing, UV-monitored thermal denaturation and docking studies all consistently indicated that GHB-7 likely binds to the bulge region of the antiterminator, reduces the flexibility of the bulge nucleotides and, overall, stabilizes the RNA secondary structure. These results begin to elucidate possible mechanisms for ligand-induced inhibition of tRNA binding to T box antiterminator RNA and contribute to the knowledge of how small molecules bind relatively simple RNA structural elements such as bulges.
Department of Chemistry and Biochemistry, Ohio University, Athens, OH 45701, USA.
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Zhou
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Acquaah-Harrison
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Bergmeier
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Hines
D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D008958:Models, Molecular; D020871:RNA Stability / Q000187:drug effects; D012329:RNA, Bacterial / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism; D058928:Riboswitch / Q000187:drug effects*; D013728:Terminator Regions, Genetic / Q000187:drug effects; D014230:Triazoles / Q000737:chemistry* / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D012329:RNA, Bacterial; D058928:Riboswitch; D014230:Triazoles; D012343:RNA, Transfer