3SNB

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.209 

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:  

  • 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 inhib ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
3C-like proteinase
A
306Human SARS coronavirusMutation(s): 0 
Find proteins for P0C6U8 (Human SARS coronavirus)
Go to UniProtKB:  P0C6U8
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Peptide aldehyde inhibitor Ac-DSFDQ-H
H
6N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Biologically Interesting Molecules 1 Unique
IDChainsNameType/Class2D Diagram3D Interactions
PRD_001118
Query on PRD_001118
HPeptide aldehyde inhibitor Ac-DSFDQ-HPolypeptide / Enzyme inhibitor

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.209 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 108.740α = 90.00
b = 81.860β = 104.26
c = 53.210γ = 90.00
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
MAR345dtbdata collection
REFMACrefinement
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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