1L7K

x-ray structure of galactose mutarotase from Lactococcus lactis complexed with galactose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.161 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

High resolution X-ray structure of galactose mutarotase from Lactococcus lactis.

Thoden, J.B.Holden, H.M.

(2002) J Biol Chem 277: 20854-20861

  • DOI: 10.1074/jbc.M201415200
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Galactose mutarotase plays a key role in normal galactose metabolism by catalyzing the interconversion of beta-D-galactose and alpha-D-galactose. Here we describe the three-dimensional architecture of galactose mutarotase from Lactococcus lactis dete ...

    Galactose mutarotase plays a key role in normal galactose metabolism by catalyzing the interconversion of beta-D-galactose and alpha-D-galactose. Here we describe the three-dimensional architecture of galactose mutarotase from Lactococcus lactis determined to 1.9-A resolution. Each subunit of the dimeric enzyme displays a distinctive beta-sandwich motif. This tertiary structural element was first identified in beta-galactosidase and subsequently observed in copper amine oxidase, hyaluronate lyase, chondroitinase, and maltose phosphorylase. Two cis-peptides are found in each subunit, namely Pro(67) and Lys(136). The active site is positioned in a rather open cleft, and the electron density corresponding to the bound galactose unequivocally demonstrates that both anomers of the substrate are present in the crystalline enzyme. Those residues responsible for anchoring the sugar to the protein include Arg(71), His(96), His(170), Asp(243), and Glu(304). Both His(96) and His(170) are strictly conserved among mutarotase amino acid sequences determined thus far. The imidazole nitrogens of these residues are located within hydrogen bonding distance to the C-5 oxygen of galactose. Strikingly, the carboxylate group of Glu(304) is situated at approximately 2.7 A from the 1'-hydroxyl group of galactose, thereby suggesting its possible role as a general acid/base group.


    Organizational Affiliation

    Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA. JBThoden@facstaff.wisc.edu



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
galactose mutarotase
A, B
347Lactococcus lactisMutation(s): 1 
Gene Names: galM
EC: 5.1.3.3
Find proteins for Q9ZB17 (Lactococcus lactis)
Go to UniProtKB:  Q9ZB17
Protein Feature View
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GLA
Query on GLA

Download CCD File 
A, B
ALPHA D-GALACTOSE
C6 H12 O6
WQZGKKKJIJFFOK-PHYPRBDBSA-N
 Ligand Interaction
NA
Query on NA

Download CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.161 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 45.2α = 90
b = 76.5β = 90
c = 211.6γ = 90
Software Package:
Software NamePurpose
TNTrefinement
FRAMBOdata collection
SAINTdata scaling
TNTphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-04-24
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description