2BIF

6-PHOSPHOFRUCTO-2-KINASE/FRUCTOSE-2,6-BISPHOSPHATASE H256A MUTANT WITH F6P IN PHOSPHATASE ACTIVE SITE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.200 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of the H256A mutant of rat testis fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase. Fructose 6-phosphate in the active site leads to mechanisms for both mutant and wild type bisphosphatase activities.

Yuen, M.H.Mizuguchi, H.Lee, Y.H.Cook, P.F.Uyeda, K.Hasemann, C.A.

(1999) J.Biol.Chem. 274: 2176-2184


  • PubMed Abstract: 
  • Fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase (Fru-6-P, 2-kinase/Fru-2,6-Pase) is a bifunctional enzyme, catalyzing the interconversion of beta-D-fructose- 6-phosphate (Fru-6-P) and fructose-2,6-bisphosphate (Fru-2,6-P2) at distinct activ ...

    Fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase (Fru-6-P, 2-kinase/Fru-2,6-Pase) is a bifunctional enzyme, catalyzing the interconversion of beta-D-fructose- 6-phosphate (Fru-6-P) and fructose-2,6-bisphosphate (Fru-2,6-P2) at distinct active sites. A mutant rat testis isozyme with an alanine replacement for the catalytic histidine (H256A) in the Fru-2,6-Pase domain retains 17% of the wild type activity (Mizuguchi, H., Cook, P. F., Tai, C-H., Hasemann, C. A., and Uyeda, K. (1998) J. Biol. Chem. 274, 2166-2175). We have solved the crystal structure of H256A to a resolution of 2. 4 A by molecular replacement. Clear electron density for Fru-6-P is found at the Fru-2,6-Pase active site, revealing the important interactions in substrate/product binding. A superposition of the H256A structure with the RT2K-Wo structure reveals no significant reorganization of the active site resulting from the binding of Fru-6-P or the H256A mutation. Using this superposition, we have built a view of the Fru-2,6-P2-bound enzyme and identify the residues responsible for catalysis. This analysis yields distinct catalytic mechanisms for the wild type and mutant proteins. The wild type mechanism would lead to an inefficient transfer of a proton to the leaving group Fru-6-P, which is consistent with a view of this event being rate-limiting, explaining the extremely slow turnover (0. 032 s-1) of the Fru-2,6-Pase in all Fru-6-P,2-kinase/Fru-2,6-Pase isozymes.


    Organizational Affiliation

    Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75235, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (6-PHOSPHOFRUCTO-2-KINASE/FRUCTOSE-2,6-BISPHOSPHATASE)
A, B
469Rattus norvegicusMutation(s): 5 
Gene Names: Pfkfb4
Find proteins for P25114 (Rattus norvegicus)
Go to UniProtKB:  P25114
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

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Download CCD File 
A, B
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
SIN
Query on SIN

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Download CCD File 
A, B
SUCCINIC ACID
C4 H6 O4
KDYFGRWQOYBRFD-UHFFFAOYSA-N
 Ligand Interaction
ANP
Query on ANP

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Download CCD File 
A
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
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
F6P
Query on F6P

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Download CCD File 
A, B
FRUCTOSE-6-PHOSPHATE
C6 H13 O9 P
BGWGXPAPYGQALX-ARQDHWQXSA-N
 Ligand Interaction
BOG
Query on BOG

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Download CCD File 
A, B
B-OCTYLGLUCOSIDE
C14 H28 O6
HEGSGKPQLMEBJL-RKQHYHRCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.200 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 61.740α = 116.90
b = 73.510β = 99.31
c = 76.700γ = 105.20
Software Package:
Software NamePurpose
X-PLORrefinement
X-PLORphasing
X-PLORmodel building
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-02-16
    Type: Initial release
  • Version 1.1: 2007-10-16
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance