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

  • 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) ...

    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)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
3C-like proteinase A301Severe acute respiratory syndrome-related coronavirusMutation(s): 0 
Gene Names: rep1a-1b
EC: 3.4.22 (PDB Primary Data), 3.4.19.12 (UniProt), 3.4.22.69 (UniProt), 2.7.7.48 (UniProt), 3.6.4.12 (UniProt), 3.6.4.13 (UniProt), 2.1.1 (UniProt), 3.1.13 (UniProt), 3.1 (UniProt)
Find proteins for P0C6X7 (Severe acute respiratory syndrome coronavirus)
Explore P0C6X7 
Go to UniProtKB:  P0C6X7
Protein Feature View
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  • Reference Sequence
  • Find similar proteins by:  Sequence   |   Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Peptide aldehyde inhibitor Ac-NSFSQ-H H6N/AMutation(s): 0 
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
ECC
Query on ECC
HL-PEPTIDE LINKINGC5 H12 N2 O2GLN
Biologically Interesting Molecules (External Reference) 1 Unique
Entity ID: 2
IDChainsNameType/Class2D Diagram3D Interactions
PRD_001117
Query on PRD_001117
HPeptide aldehyde inhibitor Ac-NSFSQ-HPolypeptide /  Enzyme inhibitor

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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