The NMR Solution Structure and Function of RPA3313: A Hypothetical Protein from R. palustris

Authors

Austin J. Lowe, University of Nebraska-LincolnFollow
Jonathan Catazaro, University of Nebraska-LincolnFollow
Cheryl Arrowsmith, University of Toronto
Robert Powers, University of Nebraska-LincolnFollow

Date of this Version

4-2016

Document Type

Poster

Citation

Spring 2016 Research Fair poster, University of Nebraska-Lincoln.

Comments

Copyright (c) 2016 Austin J. Lowe, Jonathan Catazaro, Cheryl Arrrowsmith and Robert Powers.

Abstract

Protein function elucidation often relies heavily on amino acid sequence analysis and other bioinformatics approaches. The reliance is further extended to structure homology modeling for ligand docking and protein-protein interaction mapping. However, sequence analysis of RPA3313 exposes a large, unannotated class of hypothetical proteins mostly from the Rhizobiales order. In the absence of sequence and structure information, further functional elucidation of this class of proteins has been significantly hindered. A high quality NMR structure of RPA3313 reveals that the protein forms a novel split βαβ fold with a conserved ligand binding pocket between the first β-strand and the N-terminus of the α-helix. Conserved residue analysis and protein-protein interaction prediction analyses reveal multiple protein binding sites and conserved functional residues. Results of a mass spectrometry proteomic analysis strongly point toward interaction with the ribosome and its subunits. The combined structural and proteomic analyses suggest that RPA3313 by itself or in a larger complex may assist in the transportation of substrates to or from the ribosome for further processing.