1GUP

STRUCTURE OF NUCLEOTIDYLTRANSFERASE COMPLEXED WITH UDP-GALACTOSE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Work: 0.191 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural analysis of the H166G site-directed mutant of galactose-1-phosphate uridylyltransferase complexed with either UDP-glucose or UDP-galactose: detailed description of the nucleotide sugar binding site.

Thoden, J.B.Ruzicka, F.J.Frey, P.A.Rayment, I.Holden, H.M.

(1997) Biochemistry 36: 1212-1222

  • DOI: 10.1021/bi9626517
  • Primary Citation of Related Structures:  1GUQ

  • PubMed Abstract: 
  • Galactose-1-phosphate uridylyltransferase plays a key role in galactose metabolism by catalyzing the transfer of a uridine 5'-phosphoryl group from UDP-glucose to galactose 1-phosphate. The enzyme from Escherichia coli is composed of two identical su ...

    Galactose-1-phosphate uridylyltransferase plays a key role in galactose metabolism by catalyzing the transfer of a uridine 5'-phosphoryl group from UDP-glucose to galactose 1-phosphate. The enzyme from Escherichia coli is composed of two identical subunits. The structures of the enzyme/UDP-glucose and UDP-galactose complexes, in which the catalytic nucleophile His 166 has been replaced with a glycine residue, have been determined and refined to 1.8 A resolution by single crystal X-ray diffraction analysis. Crystals employed in the investigation belonged to the space group P2(1) with unit cell dimensions of a = 68 A, b = 58 A, c = 189 A, and beta = 100 degrees and two dimers in the asymmetric unit. The models for these enzyme/substrate complexes have demonstrated that the active site of the uridylyltransferase is formed by amino acid residues contributed from both subunits in the dimer. Those amino acid residues critically involved in sugar binding include Asn 153 and Gly 159 from the first subunit and Lys 311, Phe 312, Val 314, Tyr 316, Glu 317, and Gln 323 from the second subunit. The uridylyltransferase is able to accommodate both UDP-galactose and UDP-glucose substrates by simple movements of the side chains of Glu 317 and Gln 323 and by a change in the backbone dihedral angles of Val 314. The removal of the imidazole group at position 166 results in little structural perturbation of the polypeptide chain backbone when compared to the previously determined structure for the wild-type enzyme. Instead, the cavity created by the mutation is partially compensated for by the presence of a potassium ion and its accompanying coordination sphere. As such, the mutant protein structures presented here represent valid models for understanding substrate recognition and binding in the native galactose-1-phosphate uridylyltransferase.


    Organizational Affiliation

    Department of Biochemistry, University of Wisconsin-Madison, 53705, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GALACTOSE-1-PHOSPHATE URIDYLYLTRANSFERASE
A, B, C, D
348Escherichia coli (strain K12)Gene Names: galT (galB)
EC: 2.7.7.12
Find proteins for P09148 (Escherichia coli (strain K12))
Go to UniProtKB:  P09148
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

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Download CCD File 
A, B, C, D
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
ZN
Query on ZN

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Download CCD File 
A, B, C, D
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
GDU
Query on GDU

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Download CCD File 
A, B, C, D
GALACTOSE-URIDINE-5'-DIPHOSPHATE
UDP-D-GALACTOPYRANOSE
C15 H24 N2 O17 P2
HSCJRCZFDFQWRP-ABVWGUQPSA-N
 Ligand Interaction
FE
Query on FE

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Download CCD File 
A, B, C, D
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Work: 0.191 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 68.700α = 90.00
b = 57.700β = 100.08
c = 188.700γ = 90.00
Software Package:
Software NamePurpose
SAINTdata reduction
XCALIBREdata scaling
TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-11-12
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance