Experimental Data Snapshot

  • Resolution: 1.90 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.183 

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Crystal structures of two human pyrophosphorylase isoforms in complexes with UDPGlc(Gal)NAc: role of the alternatively spliced insert in the enzyme oligomeric assembly and active site architecture.

Peneff, C.Ferrari, P.Charrier, V.Taburet, Y.Monnier, C.Zamboni, V.Winter, J.Harnois, M.Fassy, F.Bourne, Y.

(2001) EMBO J 20: 6191-6202

  • DOI: https://doi.org/10.1093/emboj/20.22.6191
  • Primary Citation of Related Structures:  
    1JV1, 1JV3, 1JVD, 1JVG

  • PubMed Abstract: 

    The recently published human genome with its relatively modest number of genes has highlighted the importance of post-transcriptional and post-translational modifications, such as alternative splicing or glycosylation, in generating the complexities of human biology. The human UDP-N-acetylglucosamine (UDPGlcNAc) pyrophosphorylases AGX1 and AGX2, which differ in sequence by an alternatively spliced 17 residue peptide, are key enzymes synthesizing UDPGlcNAc, an essential precursor for protein glycosylation. To better understand the catalytic mechanism of these enzymes and the role of the alternatively spliced segment, we have solved the crystal structures of AGX1 and AGX2 in complexes with UDPGlcNAc (at 1.9 and 2.4 A resolution, respectively) and UDPGalNAc (at 2.2 and 2.3 A resolution, respectively). Comparison with known structures classifies AGX1 and AGX2 as two new members of the SpsA-GnT I Core superfamily and, together with mutagenesis analysis, helps identify residues critical for catalysis. Most importantly, our combined structural and biochemical data provide evidence for a change in the oligomeric assembly accompanied by a significant modification of the active site architecture, a result suggesting that the two isoforms generated by alternative splicing may have distinct catalytic properties.

  • Organizational Affiliation

    AFMB, UMR 6098 CNRS, 31 chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
GlcNAc1P uridyltransferase isoform 1: AGX1
A, B
505Homo sapiensMutation(s): 0 
Gene Names: UAP1
EC: 2.7.7
UniProt & NIH Common Fund Data Resources
Find proteins for Q16222 (Homo sapiens)
Explore Q16222 
Go to UniProtKB:  Q16222
PHAROS:  Q16222
GTEx:  ENSG00000117143 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ16222
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on UD1

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
C17 H27 N3 O17 P2
Experimental Data & Validation

Experimental Data

  • Resolution: 1.90 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.183 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 85.829α = 90
b = 70.904β = 95.25
c = 96.18γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
CCP4data scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-08-28
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-04
    Changes: Refinement description
  • Version 1.4: 2024-03-13
    Changes: Data collection, Database references, Derived calculations