3HG5

Human alpha-galactosidase catalytic mechanism 4. Product bound


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.191 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Catalytic mechanism of human alpha-galactosidase.

Guce, A.I.Clark, N.E.Salgado, E.N.Ivanen, D.R.Kulminskaya, A.A.Brumer, H.Garman, S.C.

(2010) J.Biol.Chem. 285: 3625-3632

  • DOI: 10.1074/jbc.M109.060145
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The enzyme alpha-galactosidase (alpha-GAL, also known as alpha-GAL A; E.C. 3.2.1.22) is responsible for the breakdown of alpha-galactosides in the lysosome. Defects in human alpha-GAL lead to the development of Fabry disease, a lysosomal storage diso ...

    The enzyme alpha-galactosidase (alpha-GAL, also known as alpha-GAL A; E.C. 3.2.1.22) is responsible for the breakdown of alpha-galactosides in the lysosome. Defects in human alpha-GAL lead to the development of Fabry disease, a lysosomal storage disorder characterized by the buildup of alpha-galactosylated substrates in the tissues. alpha-GAL is an active target of clinical research: there are currently two treatment options for Fabry disease, recombinant enzyme replacement therapy (approved in the United States in 2003) and pharmacological chaperone therapy (currently in clinical trials). Previously, we have reported the structure of human alpha-GAL, which revealed the overall structure of the enzyme and established the locations of hundreds of mutations that lead to the development of Fabry disease. Here, we describe the catalytic mechanism of the enzyme derived from x-ray crystal structures of each of the four stages of the double displacement reaction mechanism. Use of a difluoro-alpha-galactopyranoside allowed trapping of a covalent intermediate. The ensemble of structures reveals distortion of the ligand into a (1)S(3) skew (or twist) boat conformation in the middle of the reaction cycle. The high resolution structures of each step in the catalytic cycle will allow for improved drug design efforts on alpha-GAL and other glycoside hydrolase family 27 enzymes by developing ligands that specifically target different states of the catalytic cycle. Additionally, the structures revealed a second ligand-binding site suitable for targeting by novel pharmacological chaperones.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Alpha-galactosidase A
A, B
398Homo sapiensMutation(s): 0 
Gene Names: GLA
EC: 3.2.1.22
Find proteins for P06280 (Homo sapiens)
Go to Gene View: GLA
Go to UniProtKB:  P06280
Small Molecules
Ligands 7 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
MAN
Query on MAN

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Download CCD File 
B
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
GAL
Query on GAL

Download SDF File 
Download CCD File 
B
BETA-D-GALACTOSE
C6 H12 O6
WQZGKKKJIJFFOK-FPRJBGLDSA-N
 Ligand Interaction
BMA
Query on BMA

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Download CCD File 
A, B
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
NAG
Query on NAG

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Download CCD File 
A, B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
ACY
Query on ACY

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Download CCD File 
A, B
ACETIC ACID
C2 H4 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-N
 Ligand Interaction
GLA
Query on GLA

Download SDF File 
Download CCD File 
A, B
ALPHA D-GALACTOSE
C6 H12 O6
WQZGKKKJIJFFOK-PHYPRBDBSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.191 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 90.813α = 90.00
b = 90.813β = 90.00
c = 217.166γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
PDB_EXTRACTdata extraction
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
REFMACrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-11-24
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance
  • Version 1.2: 2017-11-01
    Type: Refinement description