Dynamics of RNA-protein interactions

during ribosome assembly and gene expression

Sarah Woodson

Department of Biophysics

Johns Hopkins University

Abstract:

Although RNA can fold into intricate switches, catalysts and even nanostructures, often act together with proteins in the cell. Protein interactions not only stabilize RNA structures but chaperone RNA folding and guide the motions of the RNA helices. In the first example, we used single molecule fluorescence spectroscopy to observe the real-time assembly of ribosomal RNA-protein complexes. The results showed how protein-dependent changes in dynamical motions of the rRNA helices enable the recruitment of later proteins, producing the hierarchical assembly map. In the second example, small non-coding RNAs switch gene expression on and off by folding target mRNAs into new structures. Recent work shows how disordered regions of the Sm-protein Hfq drive efficient target recognition and sRNA competition, preventing this RNA chaperone from being sequestered by inauthentic substrates.

Selected Recent Publications:

Kilburn, D., Behrouzi, R., Lee H. T., Sarkar, K., Briber, R. M., Woodson, S. A. (2016) Entropic stabilization of folded RNA in crowded solutions measured by SAXS. Nucl. Acids. Res.

Santiago-Frangos, A., Kavita, K., Schu, D. J., Gottesman, S. and Woodson, S. A. (2016) Cterminal domain of the RNA chaperone Hfq drives sRNA competition and release of target RNA. PNAS

Stagno, J. R, et al. (2017) Structures of riboswitch RNA reaction states by mix-and-inject XFEL serial crystallography. Nature

Time: 16:30-17:30 pm, May 9th, 2017 (Tuesday)

Venue: New Biology Building, Room 143

Host: Xianyang Fang