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Structure and Mechanism of Dimer-Monomer Transition of a Plant Poly(A)-Binding Protein upon RNA Interaction: Insights into Its Poly(A) Tail Assembly.
- Source :
-
Journal of molecular biology [J Mol Biol] 2015 Jul 31; Vol. 427 (15), pp. 2491-2506. Date of Electronic Publication: 2015 May 24. - Publication Year :
- 2015
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Abstract
- Poly(A)-binding proteins (PABPs) play crucial roles in mRNA biogenesis, stability, transport and translational control in most eukaryotic cells. Although animal PABPs are well-studied proteins, the biological role, three-dimensional structure and RNA-binding mode of plant PABPs remain largely uncharacterized. Here, we report the structural features and RNA-binding mode of a Citrus sinensis PABP (CsPABPN1). CsPABPN1 has a domain architecture of nuclear PABPs (PABPNs) with a single RNA recognition motif (RRM) flanked by an acidic N-terminus and a GRPF-rich C-terminus. The RRM domain of CsPABPN1 displays virtually the same three-dimensional structure and poly(A)-binding mode of animal PABPNs. However, while the CsPABPN1 RRM domain specifically binds poly(A), the full-length protein also binds poly(U). CsPABPN1 localizes to the nucleus of plant cells and undergoes a dimer-monomer transition upon poly(A) interaction. We show that poly(A) binding by CsPABPN1 begins with the recognition of the RNA-binding sites RNP1 and RNP2, followed by interactions with residues of the β2 strands, which stabilize the dimer, thus leading to dimer dissociation. Like human PABPN1, CsPABPN1 also seems to form filaments in the presence of poly(A). Based on these data, we propose a structural model in which contiguous CsPABPN1 RRM monomers wrap around the RNA molecule creating a superhelical structure that could not only shield the poly(A) tail but also serve as a scaffold for the assembly of additional mRNA processing factors.<br /> (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Subjects :
- Amino Acid Sequence
Citrus sinensis genetics
Kinetics
Models, Molecular
Molecular Sequence Data
Protein Binding
Protein Structure, Quaternary
Protein Structure, Tertiary
RNA, Plant chemistry
Saccharomyces cerevisiae
Sequence Homology, Amino Acid
Citrus sinensis metabolism
Plant Proteins chemistry
Plant Proteins metabolism
Poly(A)-Binding Proteins chemistry
Poly(A)-Binding Proteins metabolism
Protein Multimerization
RNA, Plant metabolism
RNA-Binding Proteins chemistry
RNA-Binding Proteins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1089-8638
- Volume :
- 427
- Issue :
- 15
- Database :
- MEDLINE
- Journal :
- Journal of molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 26013164
- Full Text :
- https://doi.org/10.1016/j.jmb.2015.05.017