4Z0Z

Inactive aurone synthase (polyphenol oxidase) from natural source, sulfohistidine ~ 90 %


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.165 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Aurone synthase is a catechol oxidase with hydroxylase activity and provides insights into the mechanism of plant polyphenol oxidases.

Molitor, C.Mauracher, S.G.Rompel, A.

(2016) Proc.Natl.Acad.Sci.USA 113: E1806-E1815

  • DOI: 10.1073/pnas.1523575113
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Tyrosinases and catechol oxidases belong to the family of polyphenol oxidases (PPOs). Tyrosinases catalyze theo-hydroxylation and oxidation of phenolic compounds, whereas catechol oxidases were so far defined to lack the hydroxylation activity and ca ...

    Tyrosinases and catechol oxidases belong to the family of polyphenol oxidases (PPOs). Tyrosinases catalyze theo-hydroxylation and oxidation of phenolic compounds, whereas catechol oxidases were so far defined to lack the hydroxylation activity and catalyze solely the oxidation of o-diphenolic compounds. Aurone synthase from Coreopsis grandiflora (AUS1) is a specialized plant PPO involved in the anabolic pathway of aurones. We present, to our knowledge, the first crystal structures of a latent plant PPO, its mature active and inactive form, caused by a sulfation of a copper binding histidine. Analysis of the latent proenzyme's interface between the shielding C-terminal domain and the main core provides insights into its activation mechanisms. As AUS1 did not accept common tyrosinase substrates (tyrosine and tyramine), the enzyme is classified as a catechol oxidase. However, AUS1 showed hydroxylase activity toward its natural substrate (isoliquiritigenin), revealing that the hydroxylase activity is not correlated with the acceptance of common tyrosinase substrates. Therefore, we propose that the hydroxylase reaction is a general functionality of PPOs. Molecular dynamics simulations of docked substrate-enzyme complexes were performed, and a key residue was identified that influences the plant PPO's acceptance or rejection of tyramine. Based on the evidenced hydroxylase activity and the interactions of specific residues with the substrates during the molecular dynamics simulations, a novel catalytic reaction mechanism for plant PPOs is proposed. The presented results strongly suggest that the physiological role of plant catechol oxidases were previously underestimated, as they might hydroxylate their--so far unknown--natural substrates in vivo.


    Organizational Affiliation

    Institut für Biophysikalische Chemie, Fakultät für Chemie, Universität Wien, 1090 Vienna, Austria.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Aurone synthase
A, B, C, D
350Coreopsis grandifloraMutation(s): 0 
Find proteins for A0A075DN54 (Coreopsis grandiflora)
Go to UniProtKB:  A0A075DN54
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Aurone synthase
E, F, G, H
15Coreopsis grandifloraMutation(s): 0 
Find proteins for A0A075DN54 (Coreopsis grandiflora)
Go to UniProtKB:  A0A075DN54
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CU
Query on CU

Download SDF File 
Download CCD File 
A, B, C, D
COPPER (II) ION
Cu
JPVYNHNXODAKFH-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
HS8
Query on HS8
A, B, C, D
L-PEPTIDE LINKINGC6 H10 N3 O5 SHIS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.165 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 51.530α = 90.00
b = 183.520β = 94.50
c = 78.090γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
PHENIXrefinement
XDSdata reduction
XDSdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Austrian Science FundAustriaP25217-N28

Revision History 

  • Version 1.0: 2016-04-06
    Type: Initial release
  • Version 1.1: 2016-04-13
    Type: Database references
  • Version 1.2: 2019-02-20
    Type: Advisory, Data collection, Derived calculations