6BJL

Human ABO(H) blood group glycosyltransferase GTB D302L mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.69 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.174 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Conserved residues Arg188 and Asp302 are critical for active site organization and catalysis in human ABO(H) blood group A and B glycosyltransferases.

Gagnon, S.M.L.Legg, M.S.G.Polakowski, R.Letts, J.A.Persson, M.Lin, S.Zheng, R.B.Rempel, B.Schuman, B.Haji-Ghassemi, O.Borisova, S.N.Palcic, M.M.Evans, S.V.

(2018) Glycobiology 28: 624-636

  • DOI: 10.1093/glycob/cwy051
  • Primary Citation of Related Structures:  
    6BJI, 6BJK, 6BJJ, 6BJM, 6BJL

  • PubMed Abstract: 
  • Homologous glycosyltransferases GTA and GTB perform the final step in human ABO(H) blood group A and B antigen synthesis by transferring the sugar moiety from donor UDP-GalNAc/UDP-Gal to the terminal H antigen disaccharide acceptor. Like other GT-A fold family 6 glycosyltransferases, GTA and GTB undergo major conformational changes in two mobile regions, the C-terminal tail and internal loop, to achieve the closed, catalytic state ...

    Homologous glycosyltransferases GTA and GTB perform the final step in human ABO(H) blood group A and B antigen synthesis by transferring the sugar moiety from donor UDP-GalNAc/UDP-Gal to the terminal H antigen disaccharide acceptor. Like other GT-A fold family 6 glycosyltransferases, GTA and GTB undergo major conformational changes in two mobile regions, the C-terminal tail and internal loop, to achieve the closed, catalytic state. These changes are known to establish a salt bridge network among conserved active site residues Arg188, Asp211 and Asp302, which move to accommodate a series of discrete donor conformations while promoting loop ordering and formation of the closed enzyme state. However, the individual significance of these residues in linking these processes remains unclear. Here, we report the kinetics and high-resolution structures of GTA/GTB mutants of residues 188 and 302. The structural data support a conserved salt bridge network critical to mobile polypeptide loop organization and stabilization of the catalytically competent donor conformation. Consistent with the X-ray crystal structures, the kinetic data suggest that disruption of this salt bridge network has a destabilizing effect on the transition state, emphasizing the importance of Arg188 and Asp302 in the glycosyltransfer reaction mechanism. The salt bridge network observed in GTA/GTB structures during substrate binding appears to be conserved not only among other Carbohydrate Active EnZyme family 6 glycosyltransferases but also within both retaining and inverting GT-A fold glycosyltransferases. Our findings augment recently published crystal structures, which have identified a correlation between donor substrate conformational changes and mobile loop ordering.


    Organizational Affiliation

    Department of Biochemistry & Microbiology, University of Victoria, STN CSC, Victoria, BC, Canada.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ABO blood group (Transferase A, alpha 1-3-N-acetylgalactosaminyltransferase transferase B, alpha 1-3-galactosyltransferase)A282Homo sapiensMutation(s): 1 
Gene Names: ABO
EC: 2.4.1.40 (UniProt), 2.4.1.37 (UniProt)
UniProt & NIH Common Fund Data Resources
Find proteins for P16442 (Homo sapiens)
Explore P16442 
Go to UniProtKB:  P16442
PHAROS:  P16442
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download Ideal Coordinates CCD File 
B [auth A]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.69 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.174 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.48α = 90
b = 151.14β = 90
c = 78.44γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
d*TREKdata scaling
PDB_EXTRACTdata extraction
CrystalCleardata reduction
MOLREPphasing

Structure Validation

View Full Validation Report




Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Canadian Institutes of Health Research (CIHR)CanadaMOP-77655

Revision History  (Full details and data files)

  • Version 1.0: 2018-09-19
    Type: Initial release
  • Version 1.1: 2020-01-08
    Changes: Author supporting evidence