| Autor: |
Wang J; Graduate Program in Biochemistry and Biophysics, Rensselaer Polytechnic Institute, Troy, NY 12180., Koduru T; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180., Harish B; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180., McCallum SA; Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180., Larsen KP; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305., Patel KS; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305., Peters EV; Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY 12180., Gillilan RE; Cornell High Energy Synchrotron Source, Cornell University, Ithaca, NY 14853., Puglisi EV; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305., Puglisi JD; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305., Makhatadze G; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180., Royer CA; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, NY 12180. |
| Abstrakt: |
Conformational dynamics play essential roles in RNA function. However, detailed structural characterization of excited states of RNA remains challenging. Here, we apply high hydrostatic pressure (HP) to populate excited conformational states of tRNA Lys3 , and structurally characterize them using a combination of HP 2D-NMR, HP-SAXS (HP-small-angle X-ray scattering), and computational modeling. HP-NMR revealed that pressure disrupts the interactions of the imino protons of the uridine and guanosine U-A and G-C base pairs of tRNA Lys3 . HP-SAXS profiles showed a change in shape, but no change in overall extension of the transfer RNA (tRNA) at HP. Configurations extracted from computational ensemble modeling of HP-SAXS profiles were consistent with the NMR results, exhibiting significant disruptions to the acceptor stem, the anticodon stem, and the D-stem regions at HP. We propose that initiation of reverse transcription of HIV RNA could make use of one or more of these excited states. |
