Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.189 

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Hydrophilic peptides derived from the transframe region of Gag-Pol inhibit the HIV-1 protease.

Louis, J.M.Dyda, F.Nashed, N.T.Kimmel, A.R.Davies, D.R.

(1998) Biochemistry 37: 2105-2110

  • DOI: https://doi.org/10.1021/bi972059x
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The HIV-1 transframe region (TFR) is between the structural and functional domains of the Gag-Pol polyprotein, flanked by the nucleocapsid and the protease domains at its N and C termini, respectively. Transframe octapeptide (TFP) Phe-Leu-Arg-Glu-Asp-Leu-Ala-Phe, the N terminus of TFR, and its analogues are competitive inhibitors of the action of the mature HIV-1 protease. The smallest, most potent analogues are tripeptides: Glu-Asp-Leu and Glu-Asp-Phe with Ki values of approximately 50 and approximately 20 microM, respectively. Substitution of the acidic amino acids in the TFP by neutral amino acids and d or retro-d configurations of Glu-Asp-Leu results in an >40-fold increase in Ki. Protease inhibition by Glu-Asp-Leu is dependent on a protonated form of a group with a pKa of 3.8; unlike other inhibitors of HIV-1 protease which are highly hydrophobic, Glu-Asp-Leu is extremely soluble in water, and its binding affinity decreases with increasing NaCl concentration. However, Glu-Asp-Leu is a poor inhibitor (Ki approximately 7.5 mM) of the mammalian aspartic acid protease pepsin. X-ray crystallographic studies at pH 4.2 show that the interactions of Glu at P2 and Leu at P1 of Glu-Asp-Leu with residues of the active site of HIV-1 protease are similar to those of other product-enzyme complexes. It was not feasible to understand the interaction of intact TFP with HIV-1 protease under conditions of crystal growth due to its hydrolysis giving rise to two products. The sequence-specific, selective inhibition of the HIV-1 protease by the viral TFP suggests a role for TFP in regulating protease function during HIV-1 replication.

  • Organizational Affiliation

    Laboratory of Chemical Physics, National Institute of Diabetes, Digestive and Kidney Diseases, The National Institutes of Health, Bethesda, Maryland 20892, USA. jmlouis@helix.nih.gov

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
99Human immunodeficiency virus 1Mutation(s): 3 
EC: (PDB Primary Data), (UniProt), (UniProt), (UniProt), (UniProt), 2.7.7 (UniProt), 3.1 (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
  • Reference Sequence

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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.189 
  • R-Value Observed: 0.189 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.47α = 90
b = 86.44β = 90
c = 45.81γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1998-04-29
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Atomic model, Database references, Derived calculations, Non-polymer description, Structure summary, Version format compliance
  • Version 1.3: 2021-11-03
    Changes: Database references, Other