2AJ4

Crystal structure of Saccharomyces cerevisiae Galactokinase in complex with galactose and Mg:AMPPNP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.172 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Molecular structure of Saccharomyces cerevisiae Gal1p, a bifunctional galactokinase and transcriptional inducer

Thoden, J.B.Sellick, C.A.Timson, D.J.Reece, R.J.Holden, H.M.

(2005) J.Biol.Chem. 280: 36905-36911

  • DOI: 10.1074/jbc.M508446200

  • PubMed Abstract: 
  • Gal1p of Saccharomyces cerevisiae is capable of performing two independent cellular functions. First, it is a key enzyme in the Leloir pathway for galactose metabolism where it catalyzes the conversion of alpha-d-galactose to galactose 1-phosphate. S ...

    Gal1p of Saccharomyces cerevisiae is capable of performing two independent cellular functions. First, it is a key enzyme in the Leloir pathway for galactose metabolism where it catalyzes the conversion of alpha-d-galactose to galactose 1-phosphate. Second, it has the capacity to induce the transcription of the yeast GAL genes in response to the organism being challenged with galactose as the sole source of carbon. This latter function is normally performed by a highly related protein, Gal3p, but in its absence Gal1p can induce transcription, albeit inefficiently, both in vivo and in vitro. Here we report the x-ray structure of Gal1p in complex with alpha-d-galactose and Mg-adenosine 5'-(beta,gamma-imido)triphosphate (AMPPNP) determined to 2.4 Angstrom resolution. Overall, the enzyme displays a marked bilobal appearance with the active site being wedged between distinct N- and C-terminal domains. Despite being considerably larger than other galactokinases, Gal1p shares a similar molecular architecture with these enzymes as well as with other members of the GHMP superfamily. The extraordinary levels of similarity between Gal1p and Gal3p ( approximately 70% amino acid identity and approximately 90% similarity) have allowed a model for Gal3p to be constructed. By identifying the locations of mutations of Gal3p that result in altered transcriptional properties, we suggest potential models for Gal3p function and mechanisms for its interaction with the transcriptional inhibitor Gal80p. The GAL genetic switch has long been regarded as a paradigm for the control of gene expression in eukaryotes. Understanding the manner in which two of the proteins that function in transcriptional regulation interact with one another is an important step in determining the overall molecular mechanism of this switch.


    Organizational Affiliation

    Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Galactokinase
A, B
548Saccharomyces cerevisiae (strain ATCC 204508 / S288c)Mutation(s): 0 
Gene Names: GAL1
EC: 2.7.1.6
Find proteins for P04385 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Go to UniProtKB:  P04385
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

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Download CCD File 
A, B
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
ANP
Query on ANP

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A, B
PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER
C10 H17 N6 O12 P3
PVKSNHVPLWYQGJ-KQYNXXCUSA-N
 Ligand Interaction
MG
Query on MG

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Download CCD File 
A, B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
GLA
Query on GLA

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Download CCD File 
A, B
ALPHA D-GALACTOSE
C6 H12 O6
WQZGKKKJIJFFOK-PHYPRBDBSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.205 
  • R-Value Work: 0.172 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 63.300α = 90.00
b = 85.000β = 96.70
c = 112.300γ = 90.00
Software Package:
Software NamePurpose
PROTEUM PLUSdata collection
SAINTdata reduction
PROTEUM PLUSdata reduction
SAINTdata scaling
TNTrefinement
EPMRphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-08-30
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance