2GZ6

Crystal Structure Of Anabaena sp. CH1 N-acetyl-D-glucosamine 2-epimerase At 2.0 A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.168 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The Central Cavity from the (Alpha/Alpha)(6) Barrel Structure of Anabaena sp. CH1 N-Acetyl-d-glucosamine 2-Epimerase Contains Two Key Histidine Residues for Reversible Conversion.

Lee, Y.C.Wu, H.M.Chang, Y.N.Wang, W.C.Hsu, W.H.

(2007) J Mol Biol 367: 895-908

  • DOI: 10.1016/j.jmb.2006.11.001
  • Primary Citation of Related Structures:  
    2GZ6

  • PubMed Abstract: 
  • N-acetyl-D-glucosamine 2-epimerase (GlcNAc 2-epimerase) catalyzes the reversible epimerization between N-acetyl-D-glucosamine (GlcNAc) and N-acetyl-D-mannosamine (ManNAc). We report here the 2.0 A resolution crystal structure of the GlcNAc 2-epimerase from Anabaena sp ...

    N-acetyl-D-glucosamine 2-epimerase (GlcNAc 2-epimerase) catalyzes the reversible epimerization between N-acetyl-D-glucosamine (GlcNAc) and N-acetyl-D-mannosamine (ManNAc). We report here the 2.0 A resolution crystal structure of the GlcNAc 2-epimerase from Anabaena sp. CH1. The structure demonstrates an (alpha/alpha)(6) barrel fold, which shows structural homology with porcine GlcNAc 2-epimerase as well as a number of glycoside hydrolase enzymes and other sugar-metabolizing enzymes. One side of the barrel structure consists of short loops involved in dimer interactions. The other side of the barrel structure is comprised of long loops containing six short beta-sheets, which enclose a putative central active-site pocket. Site-directed mutagenesis of conserved residues near the N-terminal region of the inner alpha helices shows that R57, H239, E308, and H372 are strictly required for activity. E242 and R375 are also essential in catalysis. Based on the structure and kinetic analysis, H239 and H372 may serve as the key active site acid/base catalysts. These results suggest that the (alpha/alpha)(6) barrel represents a steady fold for presenting active-site residues in a cleft at the N-terminal ends of the inner alpha helices, thus forming a fine-tuned catalytic site in GlcNAc 2-epimerase.


    Organizational Affiliation

    Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
N-acetyl-D-glucosamine 2-epimerase AB388Anabaena sp. CH1Mutation(s): 0 
Gene Names: age
EC: 5.3.1.8
Find proteins for A4UA16 (Anabaena sp. CH1)
Explore A4UA16 
Go to UniProtKB:  A4UA16
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.168 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 79.267α = 90
b = 100.027β = 90
c = 104.878γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
CrystalCleardata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-02-27
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Source and taxonomy, Version format compliance