2xb2
Crystal structure of the core Mago-Y14-eIF4AIII-Barentsz-UPF3b assembly shows how the EJC is bridged to the NMD machinery
Structural highlights
DiseaseREN3B_HUMAN FG syndrome;X-linked intellectual disability with marfanoid habitus;X-linked non-syndromic intellectual disability. The disease is caused by mutations affecting the gene represented in this entry.[1] FunctionREN3B_HUMAN Involved in nonsense-mediated decay (NMD) of mRNAs containing premature stop codons by associating with the nuclear exon junction complex (EJC) and serving as link between the EJC core and NMD machinery. Recruits UPF2 at the cytoplasmic side of the nuclear envelope and the subsequent formation of an UPF1-UPF2-UPF3 surveillance complex (including UPF1 bound to release factors at the stalled ribosome) is believed to activate NMD. In cooperation with UPF2 stimulates both ATPase and RNA helicase activities of UPF1. Binds spliced mRNA upstream of exon-exon junctions. In vitro, stimulates translation; the function is independent of association with UPF2 and components of the EJC core.[2] [3] [4] [5] [6] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedIn mammals, Up-frameshift proteins (UPFs) form a surveillance complex that interacts with the exon junction complex (EJC) to elicit nonsense-mediated mRNA decay (NMD). UPF3b is the component of the surveillance complex that bridges the interaction with the EJC. Here, we report the 3.4 A resolution crystal structure of a minimal UPF3b-EJC assembly, consisting of the interacting domains of five proteins (UPF3b, MAGO, Y14, eIF4AIII, and Barentsz) together with RNA and adenylyl-imidodiphosphate. Human UPF3b binds with the C-terminal domain stretched over a composite surface formed by eIF4AIII, MAGO, and Y14. Residues that affect NMD when mutated are found at the core interacting surfaces, whereas differences between UPF3b and UPF3a map at peripheral interacting residues. Comparison with the binding mode of the protein PYM underscores how a common molecular surface of MAGO and Y14 recognizes different proteins acting at different times in the same pathway. The binding mode to eIF4AIII identifies a surface hot spot that is used by different DEAD-box proteins to recruit their regulators. Insights into the recruitment of the NMD machinery from the crystal structure of a core EJC-UPF3b complex.,Buchwald G, Ebert J, Basquin C, Sauliere J, Jayachandran U, Bono F, Le Hir H, Conti E Proc Natl Acad Sci U S A. 2010 May 17. PMID:20479275[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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