1PGP

CRYSTALLOGRAPHIC STUDY OF COENZYME, COENZYME ANALOGUE AND SUBSTRATE BINDING IN 6-PHOSPHOGLUCONATE DEHYDROGENASE: IMPLICATIONS FOR NADP SPECIFICITY AND THE ENZYME MECHANISM


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Work: 0.170 
  • R-Value Observed: 0.170 

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This is version 1.5 of the entry. See complete history


Literature

Crystallographic study of coenzyme, coenzyme analogue and substrate binding in 6-phosphogluconate dehydrogenase: implications for NADP specificity and the enzyme mechanism.

Adams, M.J.Ellis, G.H.Gover, S.Naylor, C.E.Phillips, C.

(1994) Structure 2: 651-668

  • DOI: https://doi.org/10.1016/s0969-2126(00)00066-6
  • Primary Citation of Related Structures:  
    1PGN, 1PGO, 1PGP, 1PGQ

  • PubMed Abstract: 

    The nicotinamide adenine dinucleotide phosphate (NADP)-dependent oxidative decarboxylase, 6-phosphogluconate dehydrogenase, is a major source of reduced coenzyme for synthesis. Enzymes later in the pentose phosphate pathway convert the reaction product, ribulose 5-phosphate, to ribose 5-phosphate. Crystallographic study of complexes with coenzyme and substrate explain the NADP dependence which determines the enzyme's metabolic role and support the proposed general base-general acid mechanism. The refined structures of binary coenzyme/analogue complexes show that Arg33 is ordered by binding the 2'-phosphate, and provides one face of the adenine site. The nicotinamide, while less tightly bound, is more extended when reduced than when oxidized. All substrate binding residues are conserved; the 3-hydroxyl of 6-phosphogluconate is hydrogen bonded to N zeta of Lys183 and the 3-hydrogen points towards the oxidized nicotinamide. The 6-phosphate replaces a tightly bound sulphate in the apo-enzyme. NADP specificity is achieved primarily by Arg33 which binds the 2'-phosphate but, in its absence, obscures the adenine pocket. The bound oxidized nicotinamide is syn; hydride transfer from bound substrate to the nicotinamide si- face is achieved with a small movement of the nicotinamide nucleotide. Lys183 may act as general base. A water bound to Gly130 in the coenzyme domain is the most likely acid required in decarboxylation. The dihydronicotinamide ring of NADPH competes for ligands with the 1-carboxyl of 6-phosphogluconate.


  • Organizational Affiliation

    University of Oxford, Laboratory of Molecular Biophysics, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
6-PHOSPHOGLUCONATE DEHYDROGENASE482Ovis ariesMutation(s): 0 
EC: 1.1.1.44
UniProt
Find proteins for P00349 (Ovis aries)
Explore P00349 
Go to UniProtKB:  P00349
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00349
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Binding Affinity Annotations 
IDSourceBinding Affinity
6PG PDBBind:  1PGP Kd: 2000 (nM) from 1 assay(s)
BindingDB:  1PGP Kd: 1995 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Work: 0.170 
  • R-Value Observed: 0.170 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 72.74α = 90
b = 148.4β = 90
c = 102.35γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1995-02-27
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2011-11-16
    Changes: Atomic model
  • Version 1.4: 2017-11-29
    Changes: Derived calculations, Other
  • Version 1.5: 2024-02-14
    Changes: Data collection, Database references, Derived calculations