Download MendeleyStructural Basis of Nucleic Acid Binding by Nicotiana Tabacum Glycine-Rich RNA Binding Protein: Implications for its RNA Chaperone Function
Khan, F., Boelens, R., Naqvi, S.M.S., Van Ingen, H.(2014) Nucleic Acids Res 42: 8705
- PubMed: 24957607
- DOI: https://doi.org/10.1093/nar/gku468
- Primary Citation of Related Structures:
4C7Q - PubMed Abstract:
Glycine-rich RNA-binding proteins (GR-RBPs) are involved in cold shock response of plants as RNA chaperones facilitating mRNA transport, splicing and translation. GR-RBPs are bipartite proteins containing a RNA recognition motif (RRM) followed by a glycine-rich region. Here, we studied the structural basis of nucleic acid binding of full-length Nicotiana tabacum GR-RBP1. NMR studies of NtGR-RBP1 show that the glycine-rich domain, while intrinsically disordered, is responsible for mediating self-association by transient interactions with its RRM domain (NtRRM). Both NtGR-RBP1 and NtRRM bind specifically and with low micromolar affinity to RNA and single-stranded DNA. The solution structure of NtRRM shows that it is a canonical RRM domain. A HADDOCK model of the NtRRM-RNA complex, based on NMR chemical shift and NOE data, shows that nucleic acid binding results from a combination of stacking and electrostatic interactions with conserved RRM residues. Finally, DNA melting experiments demonstrate that NtGR-RBP1 is more efficient in melting CTG containing nucleic acids than isolated NtRRM. Together, our study supports the model that self-association of GR-RBPs by the glycine-rich region results in cooperative unfolding of non-native substrate structures, thereby enhancing its chaperone function.
Organizational Affiliation:
NMR Spectroscopy Research Group, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands Department of Biochemistry, PMAS Agriculture University Rawalpindi, 46300 Rawalpindi, Pakistan.
