2WHH

HIV-1 protease tethered dimer Q-product complex along with nucleophilic water molecule


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.69 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.219 

Starting Model: experimental
View more details

wwPDB Validation   3D Report Full Report


Ligand Structure Quality Assessment 


This is version 1.3 of the entry. See complete history


Literature

Catalytic Water Co-Existing with a Product Peptide in the Active Site of HIV-1 Protease Revealed by X- Ray Structure Analysis.

Prashar, V.Bihani, S.Das, A.Ferrer, J.L.Hosur, M.V.

(2009) PLoS One 4: E7860

  • DOI: https://doi.org/10.1371/journal.pone.0007860
  • Primary Citation of Related Structures:  
    2WHH

  • PubMed Abstract: 

    It is known that HIV-1 protease is an important target for design of antiviral compounds in the treatment of Acquired Immuno Deficiency Syndrome (AIDS). In this context, understanding the catalytic mechanism of the enzyme is of crucial importance as transition state structure directs inhibitor design. Most mechanistic proposals invoke nucleophilic attack on the scissile peptide bond by a water molecule. But such a water molecule coexisting with any ligand in the active site has not been found so far in the crystal structures. We report here the first observation of the coexistence in the active site, of a water molecule WAT1, along with the carboxyl terminal product (Q product) peptide. The product peptide has been generated in situ through cleavage of the full-length substrate. The N-terminal product (P product) has diffused out and is replaced by a set of water molecules while the Q product is still held in the active site through hydrogen bonds. The position of WAT1, which hydrogen bonds to both the catalytic aspartates, is different from when there is no substrate bound in the active site. We propose WAT1 to be the position from where catalytic water attacks the scissile peptide bond. Comparison of structures of HIV-1 protease complexed with the same oligopeptide substrate, but at pH 2.0 and at pH 7.0 shows interesting changes in the conformation and hydrogen bonding interactions from the catalytic aspartates. The structure is suggestive of the repositioning, during substrate binding, of the catalytic water for activation and subsequent nucleophilic attack. The structure could be a snap shot of the enzyme active site primed for the next round of catalysis. This structure further suggests that to achieve the goal of designing inhibitors mimicking the transition-state, the hydrogen-bonding pattern between WAT1 and the enzyme should be replicated.


  • Organizational Affiliation

    Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
POL PROTEIN203Human immunodeficiency virus 1Mutation(s): 1 
EC: 3.4.23.16
UniProt
Find proteins for P04585 (Human immunodeficiency virus type 1 group M subtype B (isolate HXB2))
Explore P04585 
Go to UniProtKB:  P04585
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP04585
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.69 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.219 
  • Space Group: P 61
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.54α = 90
b = 62.54β = 90
c = 81.99γ = 120
Software Package:
Software NamePurpose
CNSrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-12-01
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-12-13
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description