2rhb | pdb_00002rhb

Crystal structure of Nsp15-H234A mutant- Hexamer in asymmetric unit

spinqualitylabelsall models 2rhb, resolution 2.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2rhb is a 6 chain structure with sequence from Cvhsa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 2h85, 2gth Gene: NSP15 (CVHSA) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [R1AB_CVHSA] The replicase polyprotein of coronaviruses is a multifunctional protein: it contains the activities necessary for the transcription of negative stranded RNA, leader RNA, subgenomic mRNAs and progeny virion RNA as well as proteinases responsible for the cleavage of the polyprotein into functional products (By similarity). The papain-like proteinase (PL-PRO) is responsible for the cleavages located at the N-terminus of replicase polyprotein. In addition, PL-PRO possesses a deubiquitinating/deISGylating activity and processes both 'Lys-48'- and 'Lys-63'-linked polyubiquitin chains from cellular substrates. Antagonizes innate immune induction of type I interferon by blocking the phosphorylation, dimerization and subsequent nuclear translocation of host IRF-3. The main proteinase 3CL-PRO is responsible for the majority of cleavages as it cleaves the C-terminus of replicase polyprotein at 11 sites. Recognizes substrates containing the core sequence [ILMVF]-Q-|-[SGACN]. Inhibited by the substrate-analog Cbz-Val-Asn-Ser-Thr-Leu-Gln-CMK (By similarity). Also contains an ADP-ribose-1-phosphate (ADRP)-binding function. The helicase which contains a zinc finger structure displays RNA and DNA duplex-unwinding activities with 5' to 3' polarity. Its ATPase activity is strongly stimulated by poly(U), poly(dT), poly(C), poly(dA), but not by poly(G). Activity of helicase is dependent on magnesium. The exoribonuclease acts on both ssRNA and dsRNA in a 3' to 5' direction. Nsp7-nsp8 hexadecamer may possibly confer processivity to the polymerase, maybe by binding to dsRNA or by producing primers utilized by the latter. Nsp9 is a ssRNA-binding protein. NendoU is a Mn(2+)-dependent, uridylate-specific enzyme, which leaves 2'-3'-cyclic phosphates 5' to the cleaved bond. 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 PubMed The severe acute respiratory syndrome (SARS) coronavirus encodes several RNA-processing enzymes that are unusual for RNA viruses, including Nsp15 (nonstructural protein 15), a hexameric endoribonuclease that preferentially cleaves 3' of uridines. We solved the structure of a catalytically inactive mutant version of Nsp15, which was crystallized as a hexamer. The structure contains unreported flexibility in the active site of each subunit. Substitutions in the active site residues serine 293 and proline 343 allowed Nsp15 to cleave at cytidylate, whereas mutation of leucine 345 rendered Nsp15 able to cleave at purines as well as pyrimidines. Mutations that targeted the residues involved in subunit interactions generally resulted in the formation of catalytically inactive monomers. The RNA-binding residues were mapped by a method linking reversible cross-linking, RNA affinity purification, and peptide fingerprinting. Alanine substitution of several residues in the RNA-contacting portion of Nsp15 did not affect hexamer formation but decreased the affinity of RNA binding and reduced endonuclease activity. This suggests a model for Nsp15 hexamer interaction with RNA. Structural and functional analyses of the severe acute respiratory syndrome coronavirus endoribonuclease Nsp15.,Bhardwaj K, Palaninathan S, Alcantara JM, Yi LL, Guarino L, Sacchettini JC, Kao CC J Biol Chem. 2008 Feb 8;283(6):3655-64. Epub 2007 Nov 28. PMID:18045871 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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