3HY8

Crystal Structure of Human Pyridoxine 5'-Phosphate Oxidase R229W Mutant


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.226 
  • R-Value Observed: 0.229 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Molecular basis of reduced pyridoxine 5'-phosphate oxidase catalytic activity in neonatal epileptic encephalopathy disorder

Musayev, F.N.Di Salvo, M.L.Saavedra, M.A.Contestabile, R.Ghatge, M.S.Haynes, A.Schirch, V.Safo, M.K.

(2009) J Biol Chem 284: 30949-30956

  • DOI: 10.1074/jbc.M109.038372
  • Primary Citation of Related Structures:  
    3HY8

  • PubMed Abstract: 
  • Mutations in pyridoxine 5'-phosphate oxidase are known to cause neonatal epileptic encephalopathy. This disorder has no cure or effective treatment and is often fatal. Pyridoxine 5'-phosphate oxidase catalyzes the oxidation of pyridoxine 5'-phosphate to pyridoxal 5'-phosphate, the active cofactor form of vitamin B(6) required by more than 140 different catalytic activities, including enzymes involved in amino acid metabolism and biosynthesis of neurotransmitters ...

    Mutations in pyridoxine 5'-phosphate oxidase are known to cause neonatal epileptic encephalopathy. This disorder has no cure or effective treatment and is often fatal. Pyridoxine 5'-phosphate oxidase catalyzes the oxidation of pyridoxine 5'-phosphate to pyridoxal 5'-phosphate, the active cofactor form of vitamin B(6) required by more than 140 different catalytic activities, including enzymes involved in amino acid metabolism and biosynthesis of neurotransmitters. Our aim is to elucidate the mechanism by which a homozygous missense mutation (R229W) in the oxidase, linked to neonatal epileptic encephalopathy, leads to reduced oxidase activity. The R229W variant is approximately 850-fold less efficient than the wild-type enzyme due to an approximately 192-fold decrease in pyridoxine 5'-phosphate affinity and an approximately 4.5-fold decrease in catalytic activity. There is also an approximately 50-fold reduction in the affinity of the R229W variant for the FMN cofactor. A 2.5 A crystal structure of the R229W variant shows that the substitution of Arg-229 at the FMN binding site has led to a loss of hydrogen-bond and/or salt-bridge interactions between FMN and Arg-229 and Ser-175. Additionally, the mutation has led to an alteration of the configuration of a beta-strand-loop-beta-strand structure at the active site, resulting in loss of two critical hydrogen-bond interactions involving residues His-227 and Arg-225, which are important for substrate binding and orientation for catalysis. These results provide a molecular basis for the phenotype associated with the R229W mutation, as well as providing a foundation for understanding the pathophysiological consequences of pyridoxine 5'-phosphate oxidase mutations.


    Organizational Affiliation

    Department of Medicinal Chemistry, School of Pharmacy, and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia 23219, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Pyridoxine-5'-phosphate oxidaseA261Homo sapiensMutation(s): 1 
Gene Names: PNPO
EC: 1.4.3.5
UniProt & NIH Common Fund Data Resources
Find proteins for Q9NVS9 (Homo sapiens)
Explore Q9NVS9 
Go to UniProtKB:  Q9NVS9
PHAROS:  Q9NVS9
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FMN
Query on FMN

Download Ideal Coordinates CCD File 
B [auth A]FLAVIN MONONUCLEOTIDE
C17 H21 N4 O9 P
FVTCRASFADXXNN-SCRDCRAPSA-N
 Ligand Interaction
PLP
Query on PLP

Download Ideal Coordinates CCD File 
C [auth A]PYRIDOXAL-5'-PHOSPHATE
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
PO4
Query on PO4

Download Ideal Coordinates CCD File 
D [auth A], E [auth A], F [auth A]PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
FMNKd:  672   nM  Binding MOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.226 
  • R-Value Observed: 0.229 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 82.27α = 90
b = 82.27β = 90
c = 58.788γ = 120
Software Package:
Software NamePurpose
d*TREKdata scaling
CNSrefinement
PDB_EXTRACTdata extraction
CrystalCleardata collection
d*TREKdata reduction
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-07-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance