2op9

Substrate Specificity Profiling and Identification of a New Class of Inhibitor for the Major Protease of the SARS Coronavirus

spinqualitylabelsall models 2op9, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2op9 is a 2 chain structure with sequence from Cvhsa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: WR1 Gene: 3Clpro (CVHSA) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 Severe acute respiratory syndrome (SARS) is an emerging infectious disease associated with a high rate of mortality. The SARS-associated coronavirus (SARS-CoV) has been identified as the etiological agent of the disease. Although public health procedures have been effective in combating the spread of SARS, concern remains about the possibility of a recurrence. Various approaches are being pursued for the development of efficacious therapeutics. One promising approach is to develop small molecule inhibitors of the essential major polyprotein processing protease 3Clpro. Here we report a complete description of the tetrapeptide substrate specificity of 3Clpro using fully degenerate peptide libraries consisting of all 160,000 possible naturally occurring tetrapeptides. The substrate specificity data show the expected P1-Gln P2-Leu specificity and elucidate a novel preference for P1-His containing substrates equal to the expected preference for P1-Gln. These data were then used to develop optimal substrates for a high-throughput screen of a 2000 compound small-molecule inhibitor library consisting of known cysteine protease inhibitor scaffolds. We also report the 1.8 A X-ray crystal structure of 3Clpro bound to an irreversible inhibitor. This inhibitor, an alpha,beta-epoxyketone, inhibits 3Clpro with a k3/Ki of 0.002 microM(-1) s(-1) in a mode consistent with the substrate specificity data. Finally, we report the successful rational improvement of this scaffold with second generation inhibitors. These data provide the foundation for a rational small-molecule inhibitor design effort based upon the inhibitor scaffold identified, the crystal structure of the complex, and a more complete understanding of P1-P4 substrate specificity. Substrate specificity profiling and identification of a new class of inhibitor for the major protease of the SARS coronavirus.,Goetz DH, Choe Y, Hansell E, Chen YT, McDowell M, Jonsson CB, Roush WR, McKerrow J, Craik CS Biochemistry. 2007 Jul 31;46(30):8744-52. Epub 2007 Jul 3. PMID:17605471 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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