title: Structural basis of nucleic acid binding by Nicotiana tabacum glycine-rich RNA-binding protein: implications for its RNA chaperone function.
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.
authors: 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.
authors: Fariha
authors: F
authors: Khan
authors: NMR Spectroscopy Research Group, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors: Mark A
authors: MA
authors: Daniëls
authors: NMR Spectroscopy Research Group, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors: Gert E
authors: GE
authors: Folkers
authors: NMR Spectroscopy Research Group, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors: Rolf
authors: R
authors: Boelens
authors: Department of Biochemistry, PMAS Agriculture University Rawalpindi, 46300 Rawalpindi, Pakistan hugo.van.ingen@gmail.com.
authors: S M
authors: SM
authors: Saqlan Naqvi
authors: NMR Spectroscopy Research Group, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands hugo.van.ingen@gmail.com.
authors: Hugo
authors: H
authors: van Ingen
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism; D009691:Nucleic Acid Denaturation; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D055672:Static Electricity; D014026:Nicotiana
chemical_list: D004277:DNA, Single-Stranded; D010940:Plant Proteins; D016601:RNA-Binding Proteins; C100791:glycine-rich RNA-binding protein, plant; D012313:RNA