IMP Complex of the Recombinant Mouse-Muscle Adenylosuccinate Synthetase

Experimental Data Snapshot

  • Resolution: 2.10 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.202 

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IMP, GTP, and 6-phosphoryl-IMP complexes of recombinant mouse muscle adenylosuccinate synthetase.

Iancu, C.V.Borza, T.Fromm, H.J.Honzatko, R.B.

(2002) J Biol Chem 277: 26779-26787

  • DOI: https://doi.org/10.1074/jbc.M203730200
  • Primary Citation of Related Structures:  
    1IWE, 1LNY, 1LON, 1LOO

  • PubMed Abstract: 

    Prokaryotes have a single form of adenylosuccinate synthetase that controls the committed step of AMP biosynthesis, but vertebrates have two isozymes of the synthetase. The basic isozyme, which predominates in muscle, participates in the purine nucleotide cycle, has an active site conformation different from that of the Escherichia coli enzyme, and exhibits significant differences in ligand recognition. Crystalline complexes presented here of the recombinant basic isozyme from mouse show the following. GTP alone binds to the active site without inducing a conformational change. IMP in combination with an acetate anion induces major conformational changes and organizes the active site for catalysis. IMP, in the absence of GTP, binds to the GTP pocket of the synthetase. The combination of GTP and IMP results in the formation of a stable complex of 6-phosphoryl-IMP and GDP in the presence or absence of hadacidin. The response of the basic isozyme to GTP alone differs from that of synthetases from plants, and yet the conformation of the mouse basic and E. coli synthetases in their complexes with GDP, 6-phosphoryl-IMP, and hadacidin are nearly identical. Hence, reported differences in ligand recognition among synthetases probably arise from conformational variations observed in partially ligated enzymes.

  • Organizational Affiliation

    Department of Biochemistry, Biophysics, and Molecular Biology, Molecular Biology Building, Iowa State University, Ames, IA 50011, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Adenylosuccinate Synthetase
A, B
457Mus musculusMutation(s): 0 
Gene Names: ADSS1
Find proteins for P28650 (Mus musculus)
Explore P28650 
Go to UniProtKB:  P28650
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP28650
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.10 Å
  • R-Value Free: 0.253 
  • R-Value Work: 0.202 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 129.89α = 90
b = 69.99β = 95.28
c = 105.33γ = 90
Software Package:
Software NamePurpose

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-08-28
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-04
    Changes: Refinement description
  • Version 1.4: 2023-10-25
    Changes: Data collection, Database references, Derived calculations, Refinement description