Experimental Data Snapshot

  • Resolution: 2.60 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.185 

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Complexes of adenosine deaminase with two potent inhibitors: X-ray structures in four independent molecules at pH of maximum activity.

Wang, Z.Quiocho, F.A.

(1998) Biochemistry 37: 8314-8324

  • DOI: https://doi.org/10.1021/bi980324o
  • Primary Citation of Related Structures:  
    1A4L, 1A4M

  • PubMed Abstract: 

    Adenosine deaminase, which catalyzes the irreversible hydrolytic deamination of adenosine nucleosides to inosine nucleosides and ammonia, is a key enzyme in purine metabolism and lymphoid development. The X-ray structures of murine adenosine deaminase with bound potent inhibitors (Ki values approximately 10(-13) M) (8R)-hydroxyl-2'-deoxycoformycin (pentostatin), a transition state analogue, and (6S)-hydroxyl-1,6-dihydropurine riboside, a reaction coordinate analogue, have been determined and refined to resolutions of 2.6 and 1.95 A, respectively. Crystals of both complexes were obtained at pH 7, where the enzyme is fully active, in an identical space group with the asymmetric unit containing four molecules. In addition to the very high degree of similarity between the four independent molecules in each complex structure, there is also considerable structural similarity of the complex with the dihydropurine riboside with that of an identical complex previously determined at pH 4.2 where the enzyme is 20% active. The interactions between the enzyme and the two analogues are extremely similar. These include the coordination of the 8R- or 6S-hydroxyl group of the analogues to the Zn2+ which mainly contributes to the strong potency and very high degree of stereospecificity of inhibition by these analogues. The interactions are further indicative of the structural and chemical requirements of substrates. These structures and recent site-directed mutagenesis have further shed light on the catalytic mechanism of the enzyme.

  • Organizational Affiliation

    Structural and Computational Biology and Molecular Biophysics Program, Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B, C, D
349Mus musculusMutation(s): 0 
Find proteins for P03958 (Mus musculus)
Explore P03958 
Go to UniProtKB:  P03958
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP03958
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.60 Å
  • R-Value Free: 0.272 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.185 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 88.929α = 90
b = 93.355β = 102.94
c = 101.953γ = 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: 1998-10-14
    Type: Initial release
  • Version 1.1: 2008-03-03
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-02
    Changes: Database references, Derived calculations, Other, Refinement description
  • Version 1.4: 2024-05-22
    Changes: Data collection