2I0S

Crystal structure of aromatic amine dehydrogenase TTQ-phenylacetaldehyde adduct


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.169 
  • R-Value Work: 0.145 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

New insights into the reductive half-reaction mechanism of aromatic amine dehydrogenase revealed by reaction with carbinolamine substrates.

Roujeinikova, A.Hothi, P.Masgrau, L.Sutcliffe, M.J.Scrutton, N.S.Leys, D.

(2007) J.Biol.Chem. 282: 23766-23777

  • DOI: 10.1074/jbc.M700677200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Aromatic amine dehydrogenase uses a tryptophan tryptophylquinone (TTQ) cofactor to oxidatively deaminate primary aromatic amines. In the reductive half-reaction, a proton is transferred from the substrate C1 to betaAsp-128 O-2, in a reaction that pro ...

    Aromatic amine dehydrogenase uses a tryptophan tryptophylquinone (TTQ) cofactor to oxidatively deaminate primary aromatic amines. In the reductive half-reaction, a proton is transferred from the substrate C1 to betaAsp-128 O-2, in a reaction that proceeds by H-tunneling. Using solution studies, kinetic crystallography, and computational simulation we show that the mechanism of oxidation of aromatic carbinolamines is similar to amine oxidation, but that carbinolamine oxidation occurs at a substantially reduced rate. This has enabled us to determine for the first time the structure of the intermediate prior to the H-transfer/reduction step. The proton-betaAsp-128 O-2 distance is approximately 3.7A, in contrast to the distance of approximately 2.7A predicted for the intermediate formed with the corresponding primary amine substrate. This difference of approximately 1.0 A is due to an unexpected conformation of the substrate moiety, which is supported by molecular dynamic simulations and reflected in the approximately 10(7)-fold slower TTQ reduction rate with phenylaminoethanol compared with that with primary amines. A water molecule is observed near TTQ C-6 and is likely derived from the collapse of the preceding carbinolamine TTQ-adduct. We suggest this water molecule is involved in consecutive proton transfers following TTQ reduction, and is ultimately repositioned near the TTQ O-7 concomitant with protein rearrangement. For all carbinolamines tested, highly stable amide-TTQ adducts are formed following proton abstraction and TTQ reduction. Slow hydrolysis of the amide occurs after, rather than prior to, TTQ oxidation and leads ultimately to a carboxylic acid product.


    Organizational Affiliation

    Manchester Interdisciplinary Biocenter, University of Manchester, Manchester M17DN, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Aromatic amine dehydrogenase
D, H
124Alcaligenes faecalisMutation(s): 0 
Gene Names: aauA
EC: 1.4.9.2
Find proteins for P84887 (Alcaligenes faecalis)
Go to UniProtKB:  P84887
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Aromatic amine dehydrogenase
A, B
360Alcaligenes faecalisMutation(s): 0 
Gene Names: aauB
EC: 1.4.9.2
Find proteins for P84888 (Alcaligenes faecalis)
Go to UniProtKB:  P84888
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HY1
Query on HY1

Download SDF File 
Download CCD File 
D, H
PHENYLACETALDEHYDE
C8 H8 O
DTUQWGWMVIHBKE-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
TTQ
Query on TTQ
D, H
L-PEPTIDE LINKINGC11 H13 N3 O3TRP
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.169 
  • R-Value Work: 0.145 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 70.619α = 90.00
b = 88.821β = 90.56
c = 79.942γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALAdata scaling
MOSFLMdata reduction
CCP4data scaling
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-04-24
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance