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 

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

  • 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. I ...

    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

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Antizyme inhibitor 1
A, B
448Mus musculusMutation(s): 0 
Gene Names: Azin1 (Oazi, Oazin)
Find proteins for O35484 (Mus musculus)
Go to UniProtKB:  O35484
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.241 
  • R-Value Work: 0.198 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 92.769α = 90.00
b = 98.389β = 90.00
c = 117.331γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
ADSCdata collection
REFMACrefinement
SOLVEphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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