2JCL

Crystal structure of alpha-1,3 Galactosyltransferase (R365K) in the absence of ligands


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.29 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Conformational Changes Induced by Binding Udp-2F-Galactose to Alpha-1,3 Galactosyltransferase-Implications for Catalysis.

Jamaluddin, H.Tumbale, P.Withers, S.G.Acharya, K.R.Brew, K.

(2007) J.Mol.Biol. 369: 1270

  • DOI: 10.1016/j.jmb.2007.04.012
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Alpha-1,3 galactosyltransferase (alpha3GT) catalyzes the transfer of galactose from UDP-galactose to beta-linked galactosides with retention of its alpha configuration. Although several complexes of alpha3GT with inhibitors and substrates have been r ...

    Alpha-1,3 galactosyltransferase (alpha3GT) catalyzes the transfer of galactose from UDP-galactose to beta-linked galactosides with retention of its alpha configuration. Although several complexes of alpha3GT with inhibitors and substrates have been reported, no structure has been determined of a complex containing intact UDP-galactose. We describe the structure of a complex containing an inhibitory analogue of UDP-galactose, UDP-2F-galactose, in a complex with the Arg365Lys mutant of alpha3GT. The inhibitor is bound in a distorted, bent configuration and comparison with the structure of the apo form of this mutant shows that the interaction induces structural changes in the enzyme, implying a role for ground state destabilization in catalysis. In addition to a general reduction in flexibility in the enzyme indicated by a large reduction in crystallographic B-factors, two loops, one centred around Trp195 and one encompassing the C-terminal 11 residues undergo large structural changes in complexes with UDP and UDP derivatives. The distorted configuration of the bound UDP-2F-galactose in its complex is stabilized, in part, by interactions with residues that are part of or near the flexible loops. Mutagenesis and truncation studies indicate that two highly conserved basic amino acid residues in the C-terminal region, Lys359 and Arg365 are important for catalysis, probably reflecting their roles in these ligand-mediated conformational changes. A second Mn(2+) cofactor has been identified in the catalytic site of a complex of the Arg365Lys with UDP, in a location that suggests it could play a role in facilitating UDP release, consistent with kinetic studies that show alpha3GT activity depends on the binding of two manganese ions. Conformational changes in the C-terminal 11 residues require an initial reorganization of the Trp195 loop and are linked to enzyme progress through the catalytic cycle, including donor substrate distortion, cleavage of the UDP-galactose bond, galactose transfer, and UDP release.


    Organizational Affiliation

    Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
N-ACETYLLACTOSAMINIDE ALPHA-1,3-GALACTOSYLTRANSFERASE
A, B
289Bos taurusMutation(s): 1 
Gene Names: GGTA1
EC: 2.4.1.87
Find proteins for P14769 (Bos taurus)
Go to UniProtKB:  P14769
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.29 Å
  • R-Value Free: 0.280 
  • R-Value Work: 0.205 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 95.930α = 90.00
b = 103.260β = 90.00
c = 121.490γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
REFMACrefinement
SCALEPACKdata scaling
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-05-22
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance