Structural highlights
Function[L7QJE0_9POXV] Decapping enzyme required for the removal of the 5'-end m7GpppN cap tethered to viral and host mRNAs to allow their decay in cells. May therefore accelerate viral and cellular mRNA turnover to eliminate competing host mRNAs and allow stage-specific synthesis of viral proteins. Acceleration of the turnover of cellular transcripts may even promote the shutoff of host protein synthesis. Does not cleave unmethylated RNAs or RNAs shorter than 24 nucleotides.[ARBA:ARBA00025519] Publication Abstract from PubMedPoxviruses encode decapping enzymes that remove the protective 5' cap from both host and viral mRNAs to commit transcripts for decay by the cellular exonuclease Xrn1. Decapping by these enzymes is critical for poxvirus pathogenicity by means of simultaneously suppressing host protein synthesis and limiting the accumulation of viral double-stranded RNA (dsRNA), a trigger for antiviral responses. Here we present a high-resolution structural view of the vaccinia virus decapping enzyme D9. This Nudix enzyme contains a domain organization different from other decapping enzymes in which a three-helix bundle is inserted into the catalytic Nudix domain. The 5' mRNA cap is positioned in a bipartite active site at the interface of the two domains. Specificity for the methylated guanosine cap is achieved by stacking between conserved aromatic residues in a manner similar to that observed in canonical cap-binding proteins VP39, eIF4E, and CBP20, and distinct from eukaryotic decapping enzyme Dcp2. Structure of the poxvirus decapping enzyme D9 reveals its mechanism of cap recognition and catalysis.,Peters JK, Tibble RW, Warminski M, Jemielity J, Gross JD Structure. 2022 Mar 2. pii: S0969-2126(22)00048-X. doi:, 10.1016/j.str.2022.02.012. PMID:35290794[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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This page was last modified 10:25, 18 May 2022.