4ZGZ

STRUCTURE OF HUMAN ANTIZYME INHIBITOR IN COMPLEX WITH A C-TERMINAL FRAGMENT OF ANTIZYME


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 5.81 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.191 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural basis of antizyme-mediated regulation of polyamine homeostasis

Wu, H.Y.Chen, S.F.Hsieh, J.Y.Chou, F.Wang, Y.H.Lin, W.T.Lee, P.Y.Yu, Y.J.Lin, L.Y.Lin, T.S.Lin, C.L.Liu, G.Y.Tzeng, S.R.Hung, H.C.Chan, N.L.

(2015) Proc Natl Acad Sci U S A 112: 11229-11234

  • DOI: 10.1073/pnas.1508187112
  • Primary Citation of Related Structures:  
    4ZGY, 4ZGZ

  • PubMed Abstract: 
  • Polyamines are organic polycations essential for cell growth and differentiation; their aberrant accumulation is often associated with diseases, including many types of cancer. To maintain polyamine homeostasis, the catalytic activity and protein abu ...

    Polyamines are organic polycations essential for cell growth and differentiation; their aberrant accumulation is often associated with diseases, including many types of cancer. To maintain polyamine homeostasis, the catalytic activity and protein abundance of ornithine decarboxylase (ODC), the committed enzyme for polyamine biosynthesis, are reciprocally controlled by the regulatory proteins antizyme isoform 1 (Az1) and antizyme inhibitor (AzIN). Az1 suppresses polyamine production by inhibiting the assembly of the functional ODC homodimer and, most uniquely, by targeting ODC for ubiquitin-independent proteolytic destruction by the 26S proteasome. In contrast, AzIN positively regulates polyamine levels by competing with ODC for Az1 binding. The structural basis of the Az1-mediated regulation of polyamine homeostasis has remained elusive. Here we report crystal structures of human Az1 complexed with either ODC or AzIN. Structural analysis revealed that Az1 sterically blocks ODC homodimerization. Moreover, Az1 binding triggers ODC degradation by inducing the exposure of a cryptic proteasome-interacting surface of ODC, which illustrates how a substrate protein may be primed upon association with Az1 for ubiquitin-independent proteasome recognition. Dynamic and functional analyses further indicated that the Az1-induced binding and degradation of ODC by proteasome can be decoupled, with the intrinsically disordered C-terminal tail fragment of ODC being required only for degradation but not binding. Finally, the AzIN-Az1 structure suggests how AzIN may effectively compete with ODC for Az1 to restore polyamine production. Taken together, our findings offer structural insights into the Az-mediated regulation of polyamine homeostasis and proteasomal degradation.


    Organizational Affiliation

    Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei 100, Taiwan; Institute of Biochemistry, National Chung Hsing University, Taichung 402, Taiwan; nlchan@ntu.edu.tw srtzeng@ntu.edu.tw hchung@dragon.nchu.edu.tw.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Antizyme inhibitor 1AC438Homo sapiensMutation(s): 1 
Gene Names: AZIN1OAZIOAZIN
Find proteins for O14977 (Homo sapiens)
Explore O14977 
Go to UniProtKB:  O14977
NIH Common Fund Data Resources
PHAROS  O14977
Protein Feature View
Expand
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Ornithine decarboxylase antizyme 1BD128Homo sapiensMutation(s): 0 
Gene Names: OAZ1OAZ
Find proteins for P54368 (Homo sapiens)
Explore P54368 
Go to UniProtKB:  P54368
NIH Common Fund Data Resources
PHAROS  P54368
Protein Feature View
Expand
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 5.81 Å
  • R-Value Free: 0.240 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.191 
  • Space Group: P 32
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 166.563α = 90
b = 166.563β = 90
c = 144.864γ = 120
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing
PHENIXrefinement

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Ministry of Science and TechnologyTaiwanNSC99-2113-M-002-008-MY3
Ministry of Science and TechnologyTaiwanNSC101-2911-I-002-303-
National Research Program for BiopharmaceuticalsTaiwanNSC101-2325-B-002-049
National Taiwan UniversityTaiwanNTU-102-027-MY3
National Taiwan UniversityTaiwanNTU-103-008-MY3

Revision History 

  • Version 1.0: 2015-09-02
    Type: Initial release
  • Version 1.1: 2015-09-16
    Changes: Database references
  • Version 1.2: 2015-10-14
    Changes: Database references