Visualizing bending of RNA structures by a bound protein using Small-Angle X-ray Scattering and Fluorescence Resonance Energy Transfer

Authors

Suzette A. Pabit ⋅ US School of Applied and Engineering Physics, Cornell University

Abstract

RNA molecules play vital roles in cellular functions, not only as facilitators of the transcription of the genetic code carried by DNA but also as non-coding molecules that promote post-transcriptional regulation of gene expression, among other functions. It is necessary to develop biophysical methods that allow visualization of the structural dynamics of non-coding RNA molecules as part of large processing complexes involving protein partners. Here, we describe how to utilize small angle x-ray scattering (SAXS) with absolute calibration and contrast variation (CV) to detect conformational changes of a primary microRNA upon binding with a part of the microprocessor complex. This method reports only on the RNA conformation within the complex and suggests that the protein bends the RNA. Supporting work using single molecule Fluorescence Energy Resonance Transfer (FRET) to study the conformation of RNA duplexes bound to the protein also shows bending. Together, these studies elucidate the role of the protein DGCR8 in interacting with RNA during the early stages of microRNA processing.

About the Speaker

Suzette A. Pabit, School of Applied and Engineering Physics, Cornell University

Suzette Atienza Pabit received her B.S. Physics degree (magna cum laude) from the National Institute of Physics, University of the Philippines Diliman under the guidance of Prof.~Roland V.~Sarmago working on condensed matter physics problems. She started working on biophysics problems as a graduate student in the University of Florida in Gainesville, Florida, USA, where she received her Ph.D. in Physics working under Prof.~Steve Hagen on the protein folding problem. She went on to acquire postdoctoral training in biophotonics in Emory University in Atlanta, Georgia, USA, and in small-angle x-ray scattering in Cornell University in Ithaca, New York, USA. She stayed on in Cornell University as part of the experimental molecular biophysics laboratory of Prof. Lois Pollack in the School of Applied and Engineering Physics. She continues to develop biophysical tools to understand protein-nucleic acid interactions.

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Issue

2020: Proceedings of the 38th Samahang Pisika ng Pilipinas Physics Conference

Article ID

SPP-2020-INV-4C-02

Section

Invited Presentations

Published

2020-10-19

How to Cite

[1]

SA Pabit, Visualizing bending of RNA structures by a bound protein using Small-Angle X-ray Scattering and Fluorescence Resonance Energy Transfer, Proceedings of the Samahang Pisika ng Pilipinas 38, SPP-2020-INV-4C-02 (2020). URL: https://proceedings.spp-online.org/article/view/SPP-2020-INV-4C-02.