1FB7

CRYSTAL STRUCTURE OF AN IN VIVO HIV-1 PROTEASE MUTANT IN COMPLEX WITH SAQUINAVIR: INSIGHTS INTO THE MECHANISMS OF DRUG RESISTANCE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Crystal structure of an in vivo HIV-1 protease mutant in complex with saquinavir: insights into the mechanisms of drug resistance.

Hong, L.Zhang, X.C.Hartsuck, J.A.Tang, J.

(2000) Protein Sci. 9: 1898-1904

  • DOI: 10.1110/ps.9.10.1898

  • PubMed Abstract: 
  • Saquinavir is a widely used HIV-1 protease inhibitor drug for AIDS therapy. Its effectiveness, however, has been hindered by the emergence of resistant mutations, a common problem for inhibitor drugs that target HIV-1 viral enzymes. Three HIV-1 prote ...

    Saquinavir is a widely used HIV-1 protease inhibitor drug for AIDS therapy. Its effectiveness, however, has been hindered by the emergence of resistant mutations, a common problem for inhibitor drugs that target HIV-1 viral enzymes. Three HIV-1 protease mutant species, G48V, L90M, and G48V/L90M double mutant, are associated in vivo with saquinavir resistance by the enzyme (Jacobsen et al., 1996). Kinetic studies on these mutants demonstrate a 13.5-, 3-, and 419-fold increase in Ki values, respectively, compared to the wild-type enzyme (Ermolieff J, Lin X, Tang J, 1997, Biochemistry 36:12364-12370). To gain an understanding of how these mutations modulate inhibitor binding, we have solved the HIV-1 protease crystal structure of the G48V/L90M double mutant in complex with saquinavir at 2.6 A resolution. This mutant complex is compared with that of the wild-type enzyme bound to the same inhibitor (Krohn A, Redshaw S, Richie JC, Graves BJ, Hatada MH, 1991, J Med Chem 34:3340-3342). Our analysis shows that to accommodate a valine side chain at position 48, the inhibitor moves away from the protease, resulting in the formation of larger gaps between the inhibitor P3 subsite and the flap region of the enzyme. Other subsites also demonstrate reduced inhibitor interaction due to an overall change of inhibitor conformation. The new methionine side chain at position 90 has van der Waals interactions with main-chain atoms of the active site residues resulting in a decrease in the volume and the structural flexibility of S1/S1' substrate binding pockets. Indirect interactions between the mutant methionine side chain and the substrate scissile bond or the isostere part of the inhibitor may differ from those of the wild-type enzyme and therefore may facilitate catalysis by the resistant mutant.


    Organizational Affiliation

    Protein Studies Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City 73104, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HIV-1 PROTEASE
A
99Human immunodeficiency virus type 1 group M subtype BMutation(s): 2 
Gene Names: gag-pol
Find proteins for P04585 (Human immunodeficiency virus type 1 group M subtype B)
Go to UniProtKB:  P04585
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ROC
Query on ROC

Download SDF File 
Download CCD File 
A
(2S)-N-[(2S,3R)-4-[(2S,3S,4aS,8aS)-3-(tert-butylcarbamoyl)-3,4,4a,5,6,7,8,8a-octahydro-1H-isoquinolin-2-yl]-3-hydroxy-1-phenyl-butan-2-yl]-2-(quinolin-2-ylcarbonylamino)butanediamide
Fortovase; SAQUINAVIR,RO 31-8959
C38 H50 N6 O5
QWAXKHKRTORLEM-UGJKXSETSA-N
 Ligand Interaction
Biologically Interesting Molecules 1 Unique
IDChainsNameType/Class2D Diagram3D Interactions
PRD_000454 (ROC)
Query on PRD_000454
ASaquinavirPeptide-like / Inhibitor

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.187 
  • Space Group: I 21 3
Unit Cell:
Length (Å)Angle (°)
a = 111.050α = 90.00
b = 111.050β = 90.00
c = 111.050γ = 90.00
Software Package:
Software NamePurpose
SADIEdata reduction
X-PLORrefinement
AMoREphasing
SAINTdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-12-13
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Atomic model, Database references, Derived calculations, Non-polymer description, Structure summary, Version format compliance
  • Version 1.3: 2013-02-27
    Type: Other