3SNA

Crystal structure of SARS coronavirus main protease complexed with Ac-NSFSQ-H (soaking)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.05 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.193 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Peptide aldehyde inhibitors challenge the substrate specificity of the SARS-coronavirus main protease.

Zhu, L.George, S.Schmidt, M.F.Al-Gharabli, S.I.Rademann, J.Hilgenfeld, R.

(2011) Antiviral Res 92: 204-212

  • DOI: https://doi.org/10.1016/j.antiviral.2011.08.001
  • Primary Citation of Related Structures:  
    3SN8, 3SNA, 3SNB, 3SNC, 3SND, 3SNE

  • PubMed Abstract: 

    SARS coronavirus main protease (SARS-CoV M(pro)) is essential for the replication of the virus and regarded as a major antiviral drug target. The enzyme is a cysteine protease, with a catalytic dyad (Cys-145/His-41) in the active site. Aldehyde inhibitors can bind reversibly to the active-site sulfhydryl of SARS-CoV M(pro). Previous studies using peptidic substrates and inhibitors showed that the substrate specificity of SARS-CoV M(pro) requires glutamine in the P1 position and a large hydrophobic residue in the P2 position. We determined four crystal structures of SARS-CoV M(pro) in complex with pentapeptide aldehydes (Ac-ESTLQ-H, Ac-NSFSQ-H, Ac-DSFDQ-H, and Ac-NSTSQ-H). Kinetic data showed that all of these aldehydes exhibit inhibitory activity towards SARS-CoV M(pro), with K(i) values in the μM range. Surprisingly, the X-ray structures revealed that the hydrophobic S2 pocket of the enzyme can accommodate serine and even aspartic-acid side-chains in the P2 positions of the inhibitors. Consequently, we reassessed the substrate specificity of the enzyme by testing the cleavage of 20 different tetradecapeptide substrates with varying amino-acid residues in the P2 position. The cleavage efficiency for the substrate with serine in the P2 position was 160-times lower than that for the original substrate (P2=Leu); furthermore, the substrate with aspartic acid in the P2 position was not cleaved at all. We also determined a crystal structure of SARS-CoV M(pro) in complex with aldehyde Cm-FF-H, which has its P1-phenylalanine residue bound to the relatively hydrophilic S1 pocket of the enzyme and yet exhibits a high inhibitory activity against SARS-CoV M(pro), with K(i)=2.24±0.58 μM. These results show that the stringent substrate specificity of the SARS-CoV M(pro) with respect to the P1 and P2 positions can be overruled by the highly electrophilic character of the aldehyde warhead, thereby constituting a deviation from the dogma that peptidic inhibitors need to correspond to the observed cleavage specificity of the target protease.


  • Organizational Affiliation

    Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
3C-like proteinase301Severe acute respiratory syndrome-related coronavirusMutation(s): 0 
EC: 3.4.22
UniProt
Find proteins for P0C6X7 (Severe acute respiratory syndrome coronavirus)
Explore P0C6X7 
Go to UniProtKB:  P0C6X7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0C6X7
Sequence Annotations
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  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Peptide aldehyde inhibitor Ac-NSFSQ-HB [auth H]6N/AMutation(s): 0 
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
ECC
Query on ECC
B [auth H]L-PEPTIDE LINKINGC5 H12 N2 O2GLN
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.05 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.193 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 107.87α = 90
b = 82.09β = 104.3
c = 53.08γ = 90
Software Package:
Software NamePurpose
MAR345dtbdata collection
AMoREphasing
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-09-07
    Type: Initial release
  • Version 1.1: 2011-09-14
    Changes: Structure summary
  • Version 1.2: 2011-11-09
    Changes: Database references
  • Version 1.3: 2012-12-12
    Changes: Other