4f02
From Proteopedia
Crystal structure of the PABP-binding site of eIF4G in complex with RRM1-2 of PABP and poly(A)
Structural highlights
Disease[IF4G1_HUMAN] Defects in EIF4G1 are the cause of Parkinson disease type 18 (PARK18) [MIM:614251]. An autosomal dominant, late-onset form of Parkinson disease. Parkinson disease is a complex neurodegenerative disorder characterized by bradykinesia, resting tremor, muscular rigidity and postural instability, as well as by a clinically significant response to treatment with levodopa. The pathology involves the loss of dopaminergic neurons in the substantia nigra and the presence of Lewy bodies (intraneuronal accumulations of aggregated proteins), in surviving neurons in various areas of the brain.[1] Function[PABP1_HUMAN] Binds the poly(A) tail of mRNA. May be involved in cytoplasmic regulatory processes of mRNA metabolism such as pre-mRNA splicing. Its function in translational initiation regulation can either be enhanced by PAIP1 or repressed by PAIP2. Can probably bind to cytoplasmic RNA sequences other than poly(A) in vivo. Involved in translationally coupled mRNA turnover. Implicated with other RNA-binding proteins in the cytoplasmic deadenylation/translational and decay interplay of the FOS mRNA mediated by the major coding-region determinant of instability (mCRD) domain. Involved in regulation of nonsense-mediated decay (NMD) of mRNAs containing premature stop codons; for the recognition of premature termination codons (PTC) and initiation of NMD a competitive interaction between UPF1 and PABPC1 with the ribosome-bound release factors is proposed.[2] [3] [IF4G1_HUMAN] Component of the protein complex eIF4F, which is involved in the recognition of the mRNA cap, ATP-dependent unwinding of 5'-terminal secondary structure and recruitment of mRNA to the ribosome. Publication Abstract from PubMedMany RNA-binding proteins contain multiple single-strand nucleic acid-binding domains and assemble into large multiprotein messenger ribonucleic acid protein (mRNP) complexes. The mechanisms underlying the self-assembly of these complexes are largely unknown. In eukaryotes, the association of the translation factors polyadenylate-binding protein-1 (PABP) and eIF4G is essential for high-level expression of polyadenylated mRNAs. Here, we report the crystal structure of the ternary complex poly(A)(11).PABP(1-190).eIF4G(178-203) at 2.0 A resolution. Our NMR and crystallographic data show that eIF4G interacts with the RRM2 domain of PABP. Analysis of the interaction by small-angle X-ray scattering, isothermal titration calorimetry, and electromobility shift assays reveals that this interaction is allosterically regulated by poly(A) binding to PABP. Furthermore, we have confirmed the importance of poly(A) for the endogenous PABP and eIF4G interaction in immunoprecipitation experiments using HeLa cell extracts. Our findings reveal interdomain allostery as a mechanism for cooperative assembly of RNP complexes. Interdomain Allostery Promotes Assembly of the Poly(A) mRNA Complex with PABP and eIF4G.,Safaee N, Kozlov G, Noronha AM, Xie J, Wilds CJ, Gehring K Mol Cell. 2012 Nov 9;48(3):375-86. doi: 10.1016/j.molcel.2012.09.001. Epub 2012, Oct 4. PMID:23041282[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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