4wmf
From Proteopedia
Crystal structure of catalytically inactive MERS-CoV 3CL protease (C148A) in spacegroup P212121
Structural highlights
FunctionW6A941_MERS Catalytic subunit of viral RNA capping enzyme which catalyzes the RNA guanylyltransferase reaction for genomic and sub-genomic RNAs. The kinase-like NiRAN domain of NSP12 transfers RNA to the amino terminus of NSP9, forming a covalent RNA-protein intermediate. Subsequently, the NiRAN domain transfers RNA to GDP, forming the core cap structure GpppA-RNA. The NSP14 and NSP16 methyltransferases then add methyl groups to form functional cap structures.[ARBA:ARBA00034461] Publication Abstract from PubMedMiddle East respiratory syndrome coronavirus (MERS-CoV) is a highly pathogenic virus that causes severe respiratory illness accompanied by multi-organ dysfunction, resulting in a case fatality rate of approximately 40%. As found in other coronaviruses, the majority of the positive-stranded RNA MERS-CoV genome is translated into two polyproteins, one created by a ribosomal frameshift, that are cleaved at three sites by a papain-like protease and at 11 sites by a 3C-like protease (3CL(pro)). Since 3CL(pro) is essential for viral replication, it is a leading candidate for therapeutic intervention. To accelerate the development of 3CL(pro) inhibitors, three crystal structures of a catalytically inactive variant (C148A) of the MERS-CoV 3CL(pro) enzyme were determined. The aim was to co-crystallize the inactive enzyme with a peptide substrate. Fortuitously, however, in two of the structures the C-terminus of one protomer is bound in the active site of a neighboring molecule, providing a snapshot of an enzyme-product complex. In the third structure, two of the three protomers in the asymmetric unit form a homodimer similar to that of SARS-CoV 3CL(pro); however, the third protomer adopts a radically different conformation that is likely to correspond to a crystallographic monomer, indicative of substantial structural plasticity in the enzyme. The results presented here provide a foundation for the structure-based design of small-molecule inhibitors of the MERS-CoV 3CL(pro) enzyme. Structures of the Middle East respiratory syndrome coronavirus 3C-like protease reveal insights into substrate specificity.,Needle D, Lountos GT, Waugh DS Acta Crystallogr D Biol Crystallogr. 2015 May;71(Pt 5):1102-11. doi:, 10.1107/S1399004715003521. Epub 2015 Apr 24. PMID:25945576[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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