1OS1

Structure of Phosphoenolpyruvate Carboxykinase complexed with ATP,Mg, Ca and pyruvate.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Mechanisms of activation of phosphoenolpyruvate carboxykinase from Escherichia coli by Ca2+ and of desensitization by trypsin.

Sudom, A.Walters, R.Pastushok, L.Goldie, D.Prasad, L.Delbaere, L.T.Goldie, H.

(2003) J.BACTERIOL. 185: 4233-4242


  • PubMed Abstract: 
  • The 1.8-A resolution structure of the ATP-Mg(2+)-Ca(2+)-pyruvate quinary complex of Escherichia coli phosphoenolpyruvate carboxykinase (PCK) is isomorphous to the published complex ATP-Mg(2+)-Mn(2+)-pyruvate-PCK, except for the Ca(2+) and Mn(2+) bind ...

    The 1.8-A resolution structure of the ATP-Mg(2+)-Ca(2+)-pyruvate quinary complex of Escherichia coli phosphoenolpyruvate carboxykinase (PCK) is isomorphous to the published complex ATP-Mg(2+)-Mn(2+)-pyruvate-PCK, except for the Ca(2+) and Mn(2+) binding sites. Ca(2+) was formerly implicated as a possible allosteric regulator of PCK, binding at the active site and at a surface activating site (Glu508 and Glu511). This report found that Ca(2+) bound only at the active site, indicating that there is likely no surface allosteric site. (45)Ca(2+) bound to PCK with a K(d) of 85 micro M and n of 0.92. Glu508Gln Glu511Gln mutant PCK had normal activation by Ca(2+). Separate roles of Mg(2+), which binds the nucleotide, and Ca(2+), which bridges the nucleotide and the anionic substrate, are implied, and the catalytic mechanism of PCK is better explained by studies of the Ca(2+)-bound structure. Partial trypsin digestion abolishes Ca(2+) activation (desensitizes PCK). N-terminal sequencing identified sensitive sites, i.e., Arg2 and Arg396. Arg2Ser, Arg396Ser, and Arg2Ser Arg396Ser (double mutant) PCKs altered the kinetics of desensitization. C-terminal residues 397 to 540 were removed by trypsin when wild-type PCK was completely desensitized. Phe409 and Phe413 interact with residues in the Ca(2+) binding site, probably stabilizing the C terminus. Phe409Ala, DeltaPhe409, Phe413Ala, Delta397-521 (deletion of residues 397 to 521), Arg396(TAA) (stop codon), and Asp269Glu (Ca(2+) site) mutations failed to desensitize PCK and, with the exception of Phe409Ala, appeared to have defects in the synthesis or assembly of PCK, suggesting that the structure of the C-terminal domain is important in these processes.


    Organizational Affiliation

    Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E5.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Phosphoenolpyruvate carboxykinase [ATP]
A
540Escherichia coli (strain K12)Gene Names: pckA (pck)
EC: 4.1.1.49
Find proteins for P22259 (Escherichia coli (strain K12))
Go to UniProtKB:  P22259
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ATP
Query on ATP

Download SDF File 
Download CCD File 
A
ADENOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O13 P3
ZKHQWZAMYRWXGA-KQYNXXCUSA-N
 Ligand Interaction
PYR
Query on PYR

Download SDF File 
Download CCD File 
A
PYRUVIC ACID
C3 H4 O3
LCTONWCANYUPML-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.200 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 126.200α = 90.00
b = 95.200β = 95.20
c = 46.800γ = 90.00
Software Package:
Software NamePurpose
CCP4data scaling
TRUNCATEdata reduction
AMoREphasing
DENZOdata reduction
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-09-23
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Source and taxonomy, Version format compliance