4DMO

Crystal structure of the (BACCR)NAT3 arylamine N-acetyltransferase from Bacillus cereus reveals a unique Cys-His-Glu catalytic triad


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.14 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.202 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural and Biochemical Characterization of an Active Arylamine N-Acetyltransferase Possessing a Non-canonical Cys-His-Glu Catalytic Triad.

Kubiak, X.Li de la Sierra-Gallay, I.Chaffotte, A.F.Pluvinage, B.Weber, P.Haouz, A.Dupret, J.M.Rodrigues-Lima, F.

(2013) J.Biol.Chem. 288: 22493-22505

  • DOI: 10.1074/jbc.M113.468595

  • PubMed Abstract: 
  • Arylamine N-acetyltransferases (NATs), a class of xenobiotic-metabolizing enzymes, catalyze the acetylation of aromatic amine compounds through a strictly conserved Cys-His-Asp catalytic triad. Each residue is essential for catalysis in both prokaryo ...

    Arylamine N-acetyltransferases (NATs), a class of xenobiotic-metabolizing enzymes, catalyze the acetylation of aromatic amine compounds through a strictly conserved Cys-His-Asp catalytic triad. Each residue is essential for catalysis in both prokaryotic and eukaryotic NATs. Indeed, in (HUMAN)NAT2 variants, mutation of the Asp residue to Asn, Gln, or Glu dramatically impairs enzyme activity. However, a putative atypical NAT harboring a catalytic triad Glu residue was recently identified in Bacillus cereus ((BACCR)NAT3) but has not yet been characterized. We report here the crystal structure and functional characterization of this atypical NAT. The overall fold of (BACCR)NAT3 and the geometry of its Cys-His-Glu catalytic triad are similar to those present in functional NATs. Importantly, the enzyme was found to be active and to acetylate prototypic arylamine NAT substrates. In contrast to (HUMAN) NAT2, the presence of a Glu or Asp in the triad of (BACCR)NAT3 did not significantly affect enzyme structure or function. Computational analysis identified differences in residue packing and steric constraints in the active site of (BACCR)NAT3 that allow it to accommodate a Cys-His-Glu triad. These findings overturn the conventional view, demonstrating that the catalytic triad of this family of acetyltransferases is plastic. Moreover, they highlight the need for further study of the evolutionary history of NATs and the functional significance of the predominant Cys-His-Asp triad in both prokaryotic and eukaryotic forms.


    Organizational Affiliation

    Université Paris Diderot, Sorbonne Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, CNRS EAC4413, 75013 Paris, France.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
N-hydroxyarylamine O-acetyltransferase
A, B
265Bacillus cereus (strain ATCC 14579 / DSM 31 / JCM 2152 / NBRC 15305 / NCIMB 9373 / NRRL B-3711)Mutation(s): 0 
EC: 2.3.1.118
Find proteins for Q81AS3 (Bacillus cereus (strain ATCC 14579 / DSM 31 / JCM 2152 / NBRC 15305 / NCIMB 9373 / NRRL B-3711))
Go to UniProtKB:  Q81AS3
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
KH2
Query on KH2

Download SDF File 
Download CCD File 
A, B
3-(1-methylpiperidinium-1-yl)propane-1-sulfonate
C9 H19 N O3 S
DQNQWAVIDNVATL-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.14 Å
  • R-Value Free: 0.255 
  • R-Value Work: 0.202 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 90.430α = 90.00
b = 44.520β = 103.80
c = 132.970γ = 90.00
Software Package:
Software NamePurpose
XDSdata scaling
RemDAqdata collection
PHASERphasing
BUSTERrefinement
PHENIXrefinement
XDSdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-06-26
    Type: Initial release
  • Version 1.1: 2013-07-03
    Type: Database references
  • Version 1.2: 2013-08-21
    Type: Database references