3BTN

Crystal structure of antizyme inhibitor, an ornithine decarboxylase homologous protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.200 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Crystallographic and biochemical studies revealing the structural basis for antizyme inhibitor function.

Albeck, S.Dym, O.Unger, T.Snapir, Z.Bercovich, Z.Kahana, C.

(2008) Protein Sci 17: 793-802

  • DOI: 10.1110/ps.073427208
  • Primary Citation of Related Structures:  
    3BTN

  • PubMed Abstract: 
  • Antizyme inhibitor (AzI) regulates cellular polyamine homeostasis by binding to the polyamine-induced protein, Antizyme (Az), with greater affinity than ornithine decarboxylase (ODC). AzI is highly homologous to ODC but is not enzymatically active. In order to understand these specific characteristics of AzI and its differences from ODC, we determined the 3D structure of mouse AzI to 2 ...

    Antizyme inhibitor (AzI) regulates cellular polyamine homeostasis by binding to the polyamine-induced protein, Antizyme (Az), with greater affinity than ornithine decarboxylase (ODC). AzI is highly homologous to ODC but is not enzymatically active. In order to understand these specific characteristics of AzI and its differences from ODC, we determined the 3D structure of mouse AzI to 2.05 A resolution. Both AzI and ODC crystallize as a dimer. However, fewer interactions at the dimer interface, a smaller buried surface area, and lack of symmetry of the interactions between residues from the two monomers in the AzI structure suggest that this dimeric structure is nonphysiological. In addition, the absence of residues and interactions required for pyridoxal 5'-phosphate (PLP) binding suggests that AzI does not bind PLP. Biochemical studies confirmed the lack of PLP binding and revealed that AzI exists as a monomer in solution while ODC is dimeric. Our findings that AzI exists as a monomer and is unable to bind PLP provide two independent explanations for its lack of enzymatic activity and suggest the basis for its enhanced affinity toward Az.


    Organizational Affiliation

    The Israel Structural Proteomics Center, Weizmann Institute of Science, Rehovot 76100, Israel.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Antizyme inhibitor 1A, B448Mus musculusMutation(s): 0 
Gene Names: Azin1OaziOazin
UniProt
Find proteins for O35484 (Mus musculus)
Explore O35484 
Go to UniProtKB:  O35484
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO35484
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.200 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 92.769α = 90
b = 98.389β = 90
c = 117.331γ = 90
Software Package:
Software NamePurpose
SOLVEphasing
REFMACrefinement
ADSCdata collection
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-04-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance