2IUP

CRYSTAL STRUCTURE OF DITHIONITE-REDUCED AROMATIC AMINE DEHYDROGENASE (AADH) FROM ALCALIGENES FAECALIS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.180 
  • R-Value Work: 0.147 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Atomic level insight into the oxidative half-reaction of aromatic amine dehydrogenase.

Roujeinikova, A.Scrutton, N.S.Leys, D.

(2006) J. Biol. Chem. 281: 40264-40272

  • DOI: 10.1074/jbc.M605559200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The quinoprotein aromatic amine dehydrogenase (AADH) uses a covalently bound tryptophan tryptophylquinone (TTQ) cofactor to oxidatively deaminate primary aromatic amines. Recent crystal structures have provided insight into the reductive half-reactio ...

    The quinoprotein aromatic amine dehydrogenase (AADH) uses a covalently bound tryptophan tryptophylquinone (TTQ) cofactor to oxidatively deaminate primary aromatic amines. Recent crystal structures have provided insight into the reductive half-reaction. In contrast, no atomic details are available for the oxidative half-reaction. The TTQ O7 hydroxyl group is protonated during reduction, but it is unclear how this proton can be removed during the oxidative half-reaction. Furthermore, compared with the electron transfer from the N-quinol form, electron transfer from the non-physiological O-quinol form to azurin is significantly slower. Here we report crystal structures of the O-quinol, N-quinol, and N-semiquinone forms of AADH. A comparison of oxidized and substrate reduced AADH species reveals changes in the TTQ-containing subunit, extending from residues in the immediate vicinity of the N-quinol to the putative azurin docking site, suggesting a mechanism whereby TTQ redox state influences interprotein electron transfer. In contrast, chemical reduction of the TTQ center has no significant effect on protein conformation. Furthermore, structural reorganization upon substrate reduction places a water molecule near TTQ O7 where it can act as proton acceptor. The structure of the N-semiquinone, however, is essentially similar to oxidized AADH. Surprisingly, in the presence of substrate a covalent N-semiquinone substrate adduct is observed. To our knowledge this is the first detailed insight into a complex, branching mechanism of quinone oxidation where significant structural reorganization upon reduction of the quinone center directly influences formation of the electron transfer complex and nature of the electron transfer process.


    Organizational Affiliation

    Manchester Interdisciplinary Biocentre, University of Manchester, Manchester M1 7DN, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
AROMATIC AMINE DEHYDROGENASE ALPHA SUBUNIT
A, B
361Alcaligenes faecalisMutation(s): 0 
Gene Names: aauB
EC: 1.4.9.2
Find proteins for P84888 (Alcaligenes faecalis)
Go to UniProtKB:  P84888
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
AROMATIC AMINE DEHYDROGENASE BETA SUBUNIT
D, H
135Alcaligenes faecalisMutation(s): 0 
Gene Names: aauA
EC: 1.4.9.2
Find proteins for P84887 (Alcaligenes faecalis)
Go to UniProtKB:  P84887
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
TRQ
Query on TRQ
D, H
L-PEPTIDE LINKINGC11 H10 N2 O4TRP
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.180 
  • R-Value Work: 0.147 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 70.960α = 90.00
b = 89.063β = 90.23
c = 80.802γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-09-20
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2019-01-30
    Type: Data collection, Experimental preparation
  • Version 1.4: 2019-02-06
    Type: Data collection, Database references, Experimental preparation