3ctr
Crystal structure of the RRM-domain of the poly(A)-specific ribonuclease PARN bound to m7GTP
Structural highlights
Function[PARN_HUMAN] 3'-exoribonuclease that has a preference for poly(A) tails of mRNAs, thereby efficiently degrading poly(A) tails. Exonucleolytic degradation of the poly(A) tail is often the first step in the decay of eukaryotic mRNAs and is also used to silence certain maternal mRNAs translationally during oocyte maturation and early embryonic development. Interacts with both the 3'-end poly(A) tail and the 5'-end cap structure during degradation, the interaction with the cap structure being required for an efficient degradation of poly(A) tails. Involved in nonsense-mediated mRNA decay, a critical process of selective degradation of mRNAs that contain premature stop codons. Also involved in degradation of inherently unstable mRNAs that contain AU-rich elements (AREs) in their 3'-UTR, possibly via its interaction with KHSRP. Probably mediates the removal of poly(A) tails of AREs mRNAs, which constitutes the first step of destabilization.[1] [2] [3] [4] [5] 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 PubMedPoly(A)-specific ribonuclease (PARN) is a processive 3'-exoribonuclease involved in the decay of eukaryotic mRNAs. Interestingly, PARN interacts not only with the 3' end of the mRNA but also with its 5' end as PARN contains an RRM domain that specifically binds both the poly(A) tail and the 7-methylguanosine (m(7)G) cap. The interaction of PARN with the 5' cap of mRNAs stimulates the deadenylation activity and enhances the processivity of this reaction. We have determined the crystal structure of the PARN-RRM domain with a bound m(7)G triphosphate nucleotide, revealing a novel binding mode for the m(7)G cap. The structure of the m(7)G binding pocket is located outside of the canonical RNA-binding surface of the RRM domain and differs significantly from that of other m(7)G-cap-binding proteins. The crystal structure also shows a remarkable conformational flexibility of the RRM domain, leading to a perfect exchange of two alpha-helices with an adjacent protein molecule in the crystal lattice. Crystal structure of the RRM domain of poly(A)-specific ribonuclease reveals a novel m(7)G-cap-binding mode.,Monecke T, Schell S, Dickmanns A, Ficner R J Mol Biol. 2008 Oct 17;382(4):827-34. Epub 2008 Jul 31. PMID:18694759[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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