1UXP

Structural basis for allosteric regulation and substrate specificity of the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN) from Thermoproteus tenax


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.55 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Basis of Allosteric Regulation and Substrate Specificity of the Non-Phosphorylating Glyceraldehyde 3-Phosphate Dehydrogenase from Thermoproteus Tenax

Lorentzen, E.Hensel, R.Knura, T.Ahmed, H.Pohl, E.

(2004) J.Mol.Biol. 341: 815

  • DOI: 10.1016/j.jmb.2004.05.032
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN) of the hyperthermophilic Archaeum Thermoproteus tenax is a member of the superfamily of aldehyde dehydrogenases (ALDH). GAPN catalyses the irreversible oxidation of glyceraldehyd ...

    The non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase (GAPN) of the hyperthermophilic Archaeum Thermoproteus tenax is a member of the superfamily of aldehyde dehydrogenases (ALDH). GAPN catalyses the irreversible oxidation of glyceraldehyde 3-phosphate (GAP) to 3-phosphoglycerate in the modified glycolytic pathway of this organism. In contrast to other members of the ALDH superfamily, GAPN from T.tenax (Tt-GAPN) is regulated by a number of intermediates and metabolites. In the NAD-dependent oxidation of GAP, glucose 1-phosphate, fructose 6-phosphate, AMP and ADP increase the affinity for the cosubstrate, whereas ATP, NADP, NADPH and NADH decrease it leaving, however, the catalytic rate virtually unaltered. As we show here, the enzyme also uses NADP as a cosubstrate, displaying, however, unusual discontinuous saturation kinetics indicating different cosubstrate affinities and/or reactivities of the four active sites of the protein tetramer caused by cooperative effects. Furthermore, in the NADP-dependent reaction the presence of activators decreases the overall S0.5 and increases Vmax by a factor of 3. To explore the structural basis for the different effects of both pyridine nucleotides we solved the crystal structure of Tt-GAPN in complex with NAD at 2.2 A resolution and compared it to the binary Tt-GAPN-NADPH structure. Although both pyridine nucleotides show a similar binding mode, NADPH appears to be more tightly bound to the protein via the 2' phosphate moiety. Moreover, we present four co-crystal structures with the activating molecules glucose 1-phosphate, fructose 6-phosphate, AMP and ADP determined at resolutions ranging from 2.3 A to 2.6 A. These crystal structures reveal a common regulatory site able to accommodate the different activators. A phosphate-binding pocket serves as an anchor point ensuring similar binding geometry. The observed conformational changes upon activator binding are discussed in terms of allosteric regulation. Furthermore, we present a crystal structure of Tt-GAPN in complex with the substrate D-GAP at 2.3 A resolution, which allows us to analyse the structural basis for substrate binding, the mechanism of catalysis as well as the stereoselectivity of the enzymatic reaction.


    Organizational Affiliation

    European Molecular Biology Laboratory, Hamburg Outstation, Notkestr. 85, D-22603 Hamburg, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE (NADP+)
A
501Thermoproteus tenaxMutation(s): 1 
Gene Names: gapN
EC: 1.2.1.90
Find proteins for O57693 (Thermoproteus tenax)
Go to UniProtKB:  O57693
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NA
Query on NA

Download SDF File 
Download CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
NAP
Query on NAP

Download SDF File 
Download CCD File 
A
NADP NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
2'-MONOPHOSPHOADENOSINE 5'-DIPHOSPHORIBOSE
C21 H28 N7 O17 P3
XJLXINKUBYWONI-NNYOXOHSSA-N
 Ligand Interaction
AMP
Query on AMP

Download SDF File 
Download CCD File 
A
ADENOSINE MONOPHOSPHATE
C10 H14 N5 O7 P
UDMBCSSLTHHNCD-KQYNXXCUSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.55 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.204 
  • Space Group: P 62 2 2
Unit Cell:
Length (Å)Angle (°)
a = 185.750α = 90.00
b = 185.750β = 90.00
c = 135.700γ = 120.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-08-05
    Type: Initial release
  • Version 1.1: 2011-05-07
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance