2f55
From Proteopedia
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Two hepatitis c virus ns3 helicase domains complexed with the same strand of dna
Overview
The hepatitis C virus (HCV) nonstructural protein 3 (NS3) is a, multifunctional enzyme with serine protease and DEXH/D-box helicase, domains. A crystal structure of the NS3 helicase domain (NS3h) was, generated in the presence of a single-stranded oligonucleotide long enough, to accommodate binding of two molecules of enzyme. Several amino acid, residues at the interface of the two NS3h molecules were identified that, appear to mediate a protein-protein interaction between domains 2 and 3 of, adjacent molecules. Mutations were introduced into domain 3 to disrupt the, putative interface and subsequently examined using an HCV subgenomic, replicon, resulting in significant reduction in replication capacity. The, mutations in domain 3 were then examined using recombinant NS3h in, biochemical assays. The mutant enzyme showed RNA binding and, RNA-stimulated ATPase activity that mirrored wild type NS3h. In DNA, unwinding assays under single turnover conditions, the mutant NS3h, exhibited a similar unwinding rate and only approximately 2-fold lower, processivity than wild type NS3h. Overall biochemical activities of the, mutant NS3h were similar to the wild type enzyme, which was not reflective, of the large reduction in HCV replicative capacity observed in the, biological experiment. Hence, the biological results suggest that the, known biochemical properties associated with the helicase activity of NS3h, do not reveal all of the likely biological roles of NS3 during HCV, replication. Domain 3 of NS3 is implicated in protein-protein interactions, that are necessary for HCV replication.
About this Structure
2F55 is a Single protein structure of sequence from Hepatitis c virus with as ligand. Full crystallographic information is available from OCA.
Reference
Structural and biological identification of residues on the surface of NS3 helicase required for optimal replication of the hepatitis C virus., Mackintosh SG, Lu JZ, Jordan JB, Harrison MK, Sikora B, Sharma SD, Cameron CE, Raney KD, Sakon J, J Biol Chem. 2006 Feb 10;281(6):3528-35. Epub 2005 Nov 22. PMID:16306038
Page seeded by OCA on Tue Jan 29 19:27:48 2008
