1LRJ

Crystal Structure of E. coli UDP-Galactose 4-Epimerase Complexed with UDP-N-Acetylglucosamine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.192 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Structural analysis of the Y299C mutant of Escherichia coli UDP-galactose 4-epimerase. Teaching an old dog new tricks.

Thoden, J.B.Henderson, J.M.Fridovich-Keil, J.L.Holden, H.M.

(2002) J.Biol.Chem. 277: 27528-27534

  • DOI: 10.1074/jbc.M204413200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • UDP-galactose 4-epimerase catalyzes the interconversion of UDP-Gal and UDP-Glc during normal galactose metabolism. The mammalian form of the enzyme, unlike its Escherichia coli counterpart, can also interconvert UDP-GalNAc and UDP-GlcNAc. One key fea ...

    UDP-galactose 4-epimerase catalyzes the interconversion of UDP-Gal and UDP-Glc during normal galactose metabolism. The mammalian form of the enzyme, unlike its Escherichia coli counterpart, can also interconvert UDP-GalNAc and UDP-GlcNAc. One key feature of the epimerase reaction mechanism is the rotation of a 4-ketopyranose intermediate in the active site. By comparing the high resolution x-ray structures of both the bacterial and human forms of the enzyme, it was previously postulated that the additional activity in the human epimerase was due to replacement of the structural equivalent of Tyr-299 in the E. coli enzyme with a cysteine residue, thereby leading to a larger active site volume. To test this hypothesis, the Y299C mutant form of the E. coli enzyme was prepared and its three-dimensional structure solved as described here. Additionally, the Y299C mutant protein was assayed for activity against both UDP-Gal and UDP-GalNAc. These studies have revealed that, indeed, this simple mutation did confer UDP-GalNAc/UDP-GlcNAc converting activity to the bacterial enzyme with minimal changes in its three-dimensional structure. Specifically, although the Y299C mutation in the bacterial enzyme resulted in a loss of epimerase activity with regard to UDP-Gal by almost 5-fold, it resulted in a gain of activity against UDP-GalNAc by more than 230-fold.


    Organizational Affiliation

    Department of Biochemistry, University of Wisconsin, Madison, WI 53706-1544, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
UDP-glucose 4-epimerase
A
338Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: galE (galD)
EC: 5.1.3.2
Find proteins for P09147 (Escherichia coli (strain K12))
Go to UniProtKB:  P09147
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
NAD
Query on NAD

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Download CCD File 
A
NICOTINAMIDE-ADENINE-DINUCLEOTIDE
C21 H27 N7 O14 P2
BAWFJGJZGIEFAR-NNYOXOHSSA-N
 Ligand Interaction
PGE
Query on PGE

Download SDF File 
Download CCD File 
A
TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N
 Ligand Interaction
UD1
Query on UD1

Download SDF File 
Download CCD File 
A
URIDINE-DIPHOSPHATE-N-ACETYLGLUCOSAMINE
C17 H27 N3 O17 P2
LFTYTUAZOPRMMI-CFRASDGPSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.192 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 83.200α = 90.00
b = 83.200β = 90.00
c = 108.300γ = 120.00
Software Package:
Software NamePurpose
TNTrefinement
FEAMBOdata reduction
SAINTdata scaling
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-07-26
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2011-11-16
    Type: Atomic model
  • Version 1.4: 2017-10-11
    Type: Refinement description