1jr6

File:1jr6.gif

spinqualitylabelsall models PDB ID 1jr6 Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
Activity:	Hepacivirin, with EC number 3.4.21.98
Resources:	FirstGlance, OCA, PDBsum, RCSB
Coordinates:	save as pdb, mmCIF, xml

Solution Structure of an Engineered Arginine-rich Subdomain 2 of the Hepatitis C Virus NS3 RNA Helicase

OverviewOverview

The NS3 protein of the hepatitis C virus (HCV) is a 631 amino acid residue bifunctional enzyme with a serine protease localized to the N-terminal 181 residues and an RNA helicase located in the C-terminal 450 residues. The HCV NS3 RNA helicase consists of three well-defined subdomains which all contribute to its helicase activity. The second subdomain of the HCV helicase is flexibly linked to the remainder of the NS3 protein and could undergo rigid-body movements during the unwinding of double-stranded RNA. It also contains several motifs that are implicated in RNA binding and in coupling NTP hydrolysis to nucleic acid unwinding and translocation. As part of our efforts to use NMR techniques to assist in deciphering the enzyme's structure-function relationships and developing specific small molecule inhibitors, we have determined the solution structure of an engineered subdomain 2 of the NS3 RNA helicase of HCV, d(2Delta)-HCVh, and studied the backbone dynamics of this protein by (15)N-relaxation experiments using a model-free approach. The NMR studies on this 142-residue construct reveal that overall subdomain 2 of the HCV helicase is globular and well structured in solution even in the absence of the remaining parts of the NS3 protein. Its solution structure is very similar to the corresponding parts in the X-ray structures of the HCV NS3 helicase domain and intact bifunctional HCV NS3 protein. Slow hydrogen-deuterium exchange rates map to a well-structured, stable hydrophobic core region away from the subdomain interfaces. In contrast, the regions facing the subdomain interfaces in the HCV NS3 helicase domain are less well structured in d(2Delta)-HCVh, show fast hydrogen-deuterium exchange rates, and the analysis of the dynamic properties of d(2Delta)-HCVh reveals that these regions of the protein show distinct dynamical features. In particular, residues in motif V, which may be involved in transducing allosteric effects of nucleotide binding and hydrolysis on RNA binding, exhibit slow conformational exchange on the milli- to microsecond time-scale. The intrinsic conformational flexibility of this loop region may facilitate conformational changes required for helicase function.

About this StructureAbout this Structure

1JR6 is a Single protein structure of sequence from Hepatitis c virus. Full crystallographic information is available from OCA.

ReferenceReference

Solution structure and backbone dynamics of an engineered arginine-rich subdomain 2 of the hepatitis C virus NS3 RNA helicase., Liu D, Wang YS, Gesell JJ, Wyss DF, J Mol Biol. 2001 Nov 30;314(3):543-61. PMID:11846566

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