1CU1

CRYSTAL STRUCTURE OF AN ENZYME COMPLEX FROM HEPATITIS C VIRUS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.200 
  • R-Value Observed: 0.200 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Molecular views of viral polyprotein processing revealed by the crystal structure of the hepatitis C virus bifunctional protease-helicase.

Yao, N.Reichert, P.Taremi, S.S.Prosise, W.W.Weber, P.C.

(1999) Structure 7: 1353-1363

  • DOI: https://doi.org/10.1016/s0969-2126(00)80025-8
  • Primary Citation of Related Structures:  
    1CU1

  • PubMed Abstract: 

    Hepatitis C virus (HCV) currently infects approximately 3% of the world's population. HCV RNA is translated into a polyprotein that during maturation is cleaved into functional components. One component, nonstructural protein 3 (NS3), is a 631-residue bifunctional enzyme with protease and helicase activities. The NS3 serine protease processes the HCV polyprotein by both cis and trans mechanisms. The structural aspects of cis processing, the autoproteolysis step whereby the protease releases itself from the polyprotein, have not been characterized. The structural basis for inclusion of protease and helicase activities in a single polypeptide is also unknown. We report here the 2.5 A resolution structure of an engineered molecule containing the complete NS3 sequence and the protease activation domain of nonstructural protein 4A (NS4A) in a single polypeptide chain (single chain or scNS3-NS4A). In the molecule, the helicase and protease domains are segregated and connected by a single strand. The helicase necleoside triphosphate and RNA interaction sites are exposed to solvent. The protease active site of scNS3-NS4A is occupied by the NS3 C terminus, which is part of the helicase domain. Thus, the intramolecular complex shows one product of NS3-mediated cleavage at the NS3-NS4A junction of the HCV polyprotein bound at the protease active site. The scNS3-NS4A structure provides the first atomic view of polyprotein cis processing. Both local and global structural rearrangements follow the cis cleavage reaction, and large segments of the polyprotein can be folded prior to proteolytic processing. That the product complex of the cis cleavage reaction exists in a stable molecular conformation suggests autoinhibition and substrate-induced activation mechanisms for regulation of NS3 protease activity.


  • Organizational Affiliation

    Structural Chemistry Department, Schering-Plough Research Institute, Kenilworth, NJ 07033-0539, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
PROTEIN (PROTEASE/HELICASE NS3)
A, B
645Hepacivirus hominisMutation(s): 0 
EC: 3.4.21
UniProt
Find proteins for P26663 (Hepatitis C virus genotype 1b (isolate BK))
Explore P26663 
Go to UniProtKB:  P26663
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP26663
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.200 
  • R-Value Observed: 0.200 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 91.36α = 90
b = 110.51β = 90
c = 141.2γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2000-08-23
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-08-23
    Changes: Source and taxonomy
  • Version 1.4: 2024-02-07
    Changes: Data collection, Database references, Derived calculations