Crystal structure of Allantoate-amidohydrolase from E.coli K12 in complex with substrate Allantoate

Experimental Data Snapshot

  • Resolution: 2.25 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.229 
  • R-Value Observed: 0.229 

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Structural analysis of a ternary complex of allantoate amidohydrolase from Escherichia coli reveals its mechanics.

Agarwal, R.Burley, S.K.Swaminathan, S.

(2007) J Mol Biol 368: 450-463

  • DOI: https://doi.org/10.1016/j.jmb.2007.02.028
  • Primary Citation of Related Structures:  
    1Z2L, 2IMO

  • PubMed Abstract: 

    Purine metabolism plays a major role in regulating the availability of purine nucleotides destined for nucleic acid synthesis. Allantoate amidohydrolase catalyzes the conversion of allantoate to (S)-ureidoglycolate, one of the crucial alternate steps in purine metabolism. The crystal structure of a ternary complex of allantoate amidohydrolase with its substrate allantoate and an allosteric effector, a sulfate ion, from Escherichia coli was determined to understand better the catalytic mechanism and substrate specificity. The 2.25 A resolution X-ray structure reveals an alpha/beta scaffold akin to zinc exopeptidases of the peptidase M20 family and lacks the (beta/alpha)(8)-barrel fold characteristic of the amidohydrolases. Arrangement of the substrate and the two co-catalytic zinc ions at the active site governs catalytic specificity for hydrolysis of N-carbamyl versus the peptide bond in exopeptidases. In its crystalline form, allantoate amidohydrolase adopts a relatively open conformation. However, structural analysis reveals the possibility of a significant movement of domains via rotation about two hinge regions upon allosteric effector and substrate binding resulting in a closed catalytically competent conformation by bringing the substrate allantoate closer to co-catalytic zinc ions. Two cis-prolyl peptide bonds found on either side of the dimerization domain in close proximity to the substrate and ligand-binding sites may be involved in protein folding and in preserving the integrity of the catalytic site.

  • Organizational Affiliation

    Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Allantoate amidohydrolase
A, B
423Escherichia coli K-12Mutation(s): 0 
Gene Names: allC
EC: 3.5.3
Find proteins for P77425 (Escherichia coli (strain K12))
Explore P77425 
Go to UniProtKB:  P77425
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP77425
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.25 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.229 
  • R-Value Observed: 0.229 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 95.532α = 90
b = 186.579β = 90
c = 49.218γ = 90
Software Package:
Software NamePurpose
MARMADdata reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-03-22
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Source and taxonomy, Version format compliance
  • Version 1.3: 2021-02-03
    Changes: Database references, Derived calculations, Structure summary
  • Version 1.4: 2024-02-14
    Changes: Data collection, Database references