1JA9

Crystal structure of 1,3,6,8-tetrahydroxynaphthalene reductase in complex with NADPH and pyroquilon


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.189 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A structural account of substrate and inhibitor specificity differences between two naphthol reductases.

Liao, D.I.Thompson, J.E.Fahnestock, S.Valent, B.Jordan, D.B.

(2001) Biochemistry 40: 8696-8704


  • PubMed Abstract: 
  • Two short chain dehydrogenase/reductases mediate naphthol reduction reactions in fungal melanin biosynthesis. An X-ray structure of 1,3,6,8-tetrahydroxynaphthalene reductase (4HNR) complexed with NADPH and pyroquilon was determined for examining subs ...

    Two short chain dehydrogenase/reductases mediate naphthol reduction reactions in fungal melanin biosynthesis. An X-ray structure of 1,3,6,8-tetrahydroxynaphthalene reductase (4HNR) complexed with NADPH and pyroquilon was determined for examining substrate and inhibitor specificities that differ from those of 1,3,8-trihydroxynaphthalene reductase (3HNR). The 1.5 A resolution structure allows for comparisons with the 1.7 A resolution structure of 3HNR complexed with the same ligands. The sequences of the two proteins are 46% identical, and they have the same fold. The 30-fold lower affinity of the 4HNR-NADPH complex for pyroquilon (a commercial fungicide that targets 3HNR) in comparison to that of the 3HNR-NADPH complex can be explained by unfavorable interactions between the anionic carboxyl group of the C-terminal Ile282 of 4HNR and CH and CH(2) groups of the inhibitor that are countered by favorable inhibitor interactions with 3HNR. 1,3,8-Trihydroxynaphthalene (3HN) and 1,3,6,8-tetrahydroxynaphthalene (4HN) were modeled onto the cyclic structure of pyroquilon in the 4HNR-NADPH-pyroquilon complex to examine the 300-fold preference of the enzyme for 4HN over 3HN. The models suggest that the C-terminal carboxyl group of Ile282 has a favorable hydrogen bonding interaction with the C6 hydroxyl group of 4HN and an unfavorable interaction with the C6 CH group of 3HN. Models of 3HN and 4HN in the 3HNR active site suggest a favorable interaction of the sulfur atom of the C-terminal Met283 with the C6 CH group of 3HN and an unfavorable one with the C6 hydroxyl group of 4HN, accounting for the 4-fold difference in substrate specificities. Thus, the C-terminal residues of the two naphthol reductase are determinants of inhibitor and substrate specificities.


    Organizational Affiliation

    Experimental Station, DuPont Central Research and Development, Wilmington, Delaware 19880, USA. der-ing.liao@usa.dupont.com




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
1,3,6,8-tetrahydroxynaphthalene reductase
A
274Magnaporthe griseaN/A
Find proteins for Q9HFV6 (Magnaporthe grisea)
Go to UniProtKB:  Q9HFV6
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PYQ
Query on PYQ

Download SDF File 
Download CCD File 
A
PYROQUILON
1,2,5,6-TETRAHYDRO-4H-PYRROLO(3,2,1-IJ)QUINOLIN-4-ONE
C11 H11 N O
XRJLAOUDSILTFT-UHFFFAOYSA-N
 Ligand Interaction
NDP
Query on NDP

Download SDF File 
Download CCD File 
A
NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE
C21 H30 N7 O17 P3
ACFIXJIJDZMPPO-NNYOXOHSSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
PYQKi: 420 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.189 
  • Space Group: P 42 21 2
Unit Cell:
Length (Å)Angle (°)
a = 94.800α = 90.00
b = 94.800β = 90.00
c = 71.200γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
X-PLORrefinement
AMoREphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-09-19
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance