5WX1

The closed-conformation crystal structure of the full-length pestivirus NS3 with its NS4A protease cofactor segment


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.196 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Uncoupling of Protease trans-Cleavage and Helicase Activities in Pestivirus NS3.

Zheng, F.Lu, G.Li, L.Gong, P.Pan, Z.

(2017) J. Virol. 91: --

  • DOI: 10.1128/JVI.01094-17

  • PubMed Abstract: 
  • The nonstructural protein NS3 from the Flaviviridae family is a multifunctional protein that contains an N-terminal protease and a C-terminal helicase, playing essential roles in viral polyprotein processing and genome replication. Here we report a f ...

    The nonstructural protein NS3 from the Flaviviridae family is a multifunctional protein that contains an N-terminal protease and a C-terminal helicase, playing essential roles in viral polyprotein processing and genome replication. Here we report a full-length crystal structure of the classical swine fever virus (CSFV) NS3 in complex with its NS4A protease cofactor segment (PCS) at a 2.35-Å resolution. The structure reveals a previously unidentified ∼2,200-Å2 intramolecular protease-helicase interface comprising three clusters of interactions, representing a "closed" global conformation related to the NS3-NS4A cis-cleavage event. Although this conformation is incompatible with protease trans-cleavage, it appears to be functionally important and beneficial to the helicase activity, as the mutations designed to perturb this conformation impaired both the helicase activities in vitro and virus production in vivo Our work reveals important features of protease-helicase coordination in pestivirus NS3 and provides a key basis for how different conformational states may explicitly contribute to certain functions of this natural protease-helicase fusion protein.IMPORTANCE Many RNA viruses encode helicases to aid their RNA genome replication and transcription by unwinding structured RNA. Being naturally fused to a protease participating in viral polyprotein processing, the NS3 helicases encoded by the Flaviviridae family viruses are unique. Therefore, how these two enzyme modules coordinate in a single polypeptide is of particular interest. Here we report a previously unidentified conformation of pestivirus NS3 in complex with its NS4A protease cofactor segment (PCS). This conformational state is related to the protease cis-cleavage event and is optimal for the function of helicase. This work provides an important basis to understand how different enzymatic activities of NS3 may be achieved by the coordination between the protease and helicase through different conformational states.


    Organizational Affiliation

    State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Serine protease NS3
A
733Classical swine fever virusMutation(s): 1 
Find proteins for Q5U8X5 (Classical swine fever virus)
Go to UniProtKB:  Q5U8X5
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.196 
  • Space Group: P 42 21 2
Unit Cell:
Length (Å)Angle (°)
a = 111.084α = 90.00
b = 111.084β = 90.00
c = 139.032γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data collection
PHASERphasing
PHENIXrefinement
HKL-2000data scaling
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Ministry of Science and TechnologyChina2013CB911100
National Natural Science FoundationChina31670154
Ministry of Science and TechnologyChina2016YFC1200400

Revision History 

  • Version 1.0: 2017-08-23
    Type: Initial release
  • Version 1.1: 2017-09-13
    Type: Database references
  • Version 1.2: 2017-12-13
    Type: Database references