2AN9

Crystal Structure Of Oligomeric E.coli Guanylate Kinase In Complex With GDP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.189 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Calorimetric and crystallographic analysis of the oligomeric structure of Escherichia coli GMP kinase

Hible, G.Renault, L.Schaeffer, F.Christova, P.Radulescu, A.Z.Evrin, C.Gilles, A.M.Cherfils, J.

(2005) J Mol Biol 352: 1044-1059

  • DOI: 10.1016/j.jmb.2005.07.042
  • Primary Citation of Related Structures:  
    2AN9, 2ANC, 2ANB

  • PubMed Abstract: 
  • Guanosine monophosphate kinases (GMPKs), which catalyze the phosphorylation of GMP and dGMP to their diphosphate form, have been characterized as monomeric enzymes in eukaryotes and prokaryotes. Here, we report that GMPK from Escherichia coli (ecGMPK ...

    Guanosine monophosphate kinases (GMPKs), which catalyze the phosphorylation of GMP and dGMP to their diphosphate form, have been characterized as monomeric enzymes in eukaryotes and prokaryotes. Here, we report that GMPK from Escherichia coli (ecGMPK) assembles in solution and in the crystal as several different oligomers. Thermodynamic analysis of ecGMPK using differential scanning calorimetry shows that the enzyme is in equilibrium between a dimer and higher order oligomers, whose relative amounts depend on protein concentration, ionic strength, and the presence of ATP. Crystallographic structures of ecGMPK in the apo, GMP and GDP-bound forms were solved at 3.2A, 2.9A and 2.4A resolution, respectively. ecGMPK forms a hexamer with D3 symmetry in all crystal forms, in which the two nucleotide-binding domains are able to undergo closure comparable to that of monomeric GMPKs. The 2-fold and 3-fold interfaces involve a 20-residue C-terminal extension and a sequence signature, respectively, that are missing from monomeric eukaryotic GMPKs, explaining why ecGMPK forms oligomers. These signatures are found in GMPKs from proteobacteria, some of which are human pathogens. GMPKs from these bacteria are thus likely to form the same quaternary structures. The shift of the thermodynamic equilibrium towards the dimer at low ecGMPK concentration together with the observation that inter-subunit interactions partially occlude the ATP-binding site in the hexameric structure suggest that the dimer may be the active species at physiological enzyme concentration.


    Organizational Affiliation

    Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Gif sur Yvette 91198, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Guanylate kinaseAB207Escherichia coliMutation(s): 0 
Gene Names: gmk
EC: 2.7.4.8
Find proteins for P60546 (Escherichia coli (strain K12))
Explore P60546 
Go to UniProtKB:  P60546
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GDP
Query on GDP

Download CCD File 
A, B
GUANOSINE-5'-DIPHOSPHATE
C10 H15 N5 O11 P2
QGWNDRXFNXRZMB-UUOKFMHZSA-N
 Ligand Interaction
GMP
Query on GMP

Download CCD File 
A, B
GUANOSINE
C10 H13 N5 O5
NYHBQMYGNKIUIF-UUOKFMHZSA-N
 Ligand Interaction
K
Query on K

Download CCD File 
A, B
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.35 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.189 
  • Space Group: P 63
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 68.225α = 90
b = 68.225β = 90
c = 151.272γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XSCALEdata scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

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