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-Structure paper
Title | Structural basis of amino acid surveillance by higher-order tRNA-mRNA interactions. |
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Journal, issue, pages | Nat Struct Mol Biol, Vol. 26, Issue 12, Page 1094-1105, Year 2019 |
Publish date | Nov 18, 2019 |
Authors | Shuang Li / Zhaoming Su / Jean Lehmann / Vassiliki Stamatopoulou / Nikoleta Giarimoglou / Frances E Henderson / Lixin Fan / Grigore D Pintilie / Kaiming Zhang / Muyuan Chen / Steven J Ludtke / Yun-Xing Wang / Constantinos Stathopoulos / Wah Chiu / Jinwei Zhang / |
PubMed Abstract | Amino acid availability in Gram-positive bacteria is monitored by T-box riboswitches. T-boxes directly bind tRNAs, assess their aminoacylation state, and regulate the transcription or translation of ...Amino acid availability in Gram-positive bacteria is monitored by T-box riboswitches. T-boxes directly bind tRNAs, assess their aminoacylation state, and regulate the transcription or translation of downstream genes to maintain nutritional homeostasis. Here, we report cocrystal and cryo-EM structures of Geobacillus kaustophilus and Bacillus subtilis T-box-tRNA complexes, detailing their multivalent, exquisitely selective interactions. The T-box forms a U-shaped molecular vise that clamps the tRNA, captures its 3' end using an elaborate 'discriminator' structure, and interrogates its aminoacylation state using a steric filter fashioned from a wobble base pair. In the absence of aminoacylation, T-boxes clutch tRNAs and form a continuously stacked central spine, permitting transcriptional readthrough or translation initiation. A modeled aminoacyl disrupts tRNA-T-box stacking, severing the central spine and blocking gene expression. Our data establish a universal mechanism of amino acid sensing on tRNAs and gene regulation by T-box riboswitches and exemplify how higher-order RNA-RNA interactions achieve multivalency and specificity. |
External links | Nat Struct Mol Biol / PubMed:31740854 / PubMed Central |
Methods | EM (single particle) / X-ray diffraction |
Resolution | 2.65703362888 - 4.9 Å |
Structure data | EMDB-20416, PDB-6pom: PDB-6pmo: |
Chemicals | ChemComp-IR: ChemComp-MG: ChemComp-HOH: |
Source |
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Keywords | RNA / Riboswitch / tRNA / RNA complex / transcription attenuation / stacking. |