2C70

Functional Role of the Aromatic Cage in Human Monoamine Oxidase B: Structures and Catalytic Properties of Tyr435 Mutant Proteins


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.06 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.188 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Functional Role of the Aromatic Cage in Human Monoamine Oxidase B: Structures and Catalytic Properties of Tyr435 Mutant Proteins

Li, M.Binda, C.Mattevi, A.Edmondson, D.E.

(2006) Biochemistry 45: 4775

  • DOI: 10.1021/bi051847g
  • Primary Citation of Related Structures:  2C72, 2C73, 2C75, 2C76

  • PubMed Abstract: 
  • Current structural results of several flavin-dependent amine oxidizing enzymes including human monoamine oxidases A and B (MAO A and MAO B) show aromatic amino acid residues oriented approximately perpendicular to the flavin ring, suggesting a functi ...

    Current structural results of several flavin-dependent amine oxidizing enzymes including human monoamine oxidases A and B (MAO A and MAO B) show aromatic amino acid residues oriented approximately perpendicular to the flavin ring, suggesting a functional role in catalysis. In the case of human MAO B, two tyrosyl residues (Y398 and Y435) are found in the substrate binding site on the re face of the covalent flavin ring [Binda et al. (2002) J. Biol. Chem. 277, 23973-23976]. To probe the functional significance of this structure, Tyr435 in MAO B was mutated with the amino acids Phe, His, Leu, or Trp, the mutant proteins expressed in Pichia pastoris, and purified to homogeneity. Each mutant protein contains covalent FAD and exhibits a high level of catalytic functionality. No major alterations in active site structures are detected on comparison of their respective crystal structures with that of WT enzyme. The relative k(cat)/K(m) values for each mutant enzyme show Y435 > Y435F = Y435L = Y435H > Y435W. A similar behavior is also observed with the membrane-bound forms of MAO A and MAO B (MAO A Y444 mutant enzymes are found to be unstable on membrane extraction). p-Nitrobenzylamine is found to be a poor substrate while p-nitrophenethylamine is found to be a good substrate for all WT and mutant forms of MAO B. Analysis of these kinetic and structural data suggests the function of the "aromatic cage" in MAO to include a steric role in substrate binding and access to the flavin coenzyme and to increase the nucleophilicity of the substrate amine moiety. These results are consistent with a proposed polar nucleophilic mechanism for catalytic amine oxidation.


    Organizational Affiliation

    Department of Biochemistry, Emory University, 1510 Clifton Road, Atlanta, Georgia 30322, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
AMINE OXIDASE (FLAVIN-CONTAINING) B
A, B
520Homo sapiensGene Names: MAOB
EC: 1.4.3.4
Find proteins for P27338 (Homo sapiens)
Go to Gene View: MAOB
Go to UniProtKB:  P27338
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FAD
Query on FAD

Download SDF File 
Download CCD File 
A, B
FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
 Ligand Interaction
PNZ
Query on PNZ

Download SDF File 
Download CCD File 
A, B
P-NITRO-BENZYLAMINE
C7 H8 N2 O2
ODVBBZFQPGORMJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.06 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.188 
  • Space Group: C 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 130.681α = 90.00
b = 222.928β = 90.00
c = 86.451γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALAdata scaling
AMoREphasing
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-04-19
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance