5CHR

Dehaloperoxidase B in complex with substrate p-nitrocatechol


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.98 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.170 

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Ligand Structure Quality Assessment 


This is version 1.4 of the entry. See complete history


Literature

Nonmicrobial Nitrophenol Degradation via Peroxygenase Activity of Dehaloperoxidase-Hemoglobin from Amphitrite ornata.

McCombs, N.L.D'Antonio, J.Barrios, D.A.Carey, L.M.Ghiladi, R.A.

(2016) Biochemistry 55: 2465-2478

  • DOI: https://doi.org/10.1021/acs.biochem.6b00143
  • Primary Citation of Related Structures:  
    5CHQ, 5CHR

  • PubMed Abstract: 

    The marine hemoglobin dehaloperoxidase (DHP) from Amphitrite ornata was found to catalyze the H2O2-dependent oxidation of nitrophenols, an unprecedented nonmicrobial degradation pathway for nitrophenols by a hemoglobin. Using 4-nitrophenol (4-NP) as a representative substrate, the major monooxygenated product was 4-nitrocatechol (4-NC). Isotope labeling studies confirmed that the O atom incorporated was derived exclusively from H2O2, indicative of a peroxygenase mechanism for 4-NP oxidation. Accordingly, X-ray crystal structures of 4-NP (1.87 Å) and 4-NC (1.98 Å) bound to DHP revealed a binding site in close proximity to the heme cofactor. Peroxygenase activity could be initiated from either the ferric or oxyferrous states with equivalent substrate conversion and product distribution. The 4-NC product was itself a peroxidase substrate for DHP, leading to the secondary products 5-nitrobenzene-triol and hydroxy-5-nitro-1,2-benzoquinone. DHP was able to react with 2,4-dinitrophenol (2,4-DNP) but was unreactive against 2,4,6-trinitrophenol (2,4,6-TNP). pH dependence studies demonstrated increased reactivity at lower pH for both 4-NP and 2,4-DNP, suggestive of a pH effect that precludes the reaction with 2,4,6-TNP at or near physiological conditions. Stopped-flow UV-visible spectroscopic studies strongly implicate a role for Compound I in the mechanism of 4-NP oxidation. The results demonstrate that there may be a much larger number of nonmicrobial enzymes that are underrepresented when it comes to understanding the degradation of persistent organic pollutants such as nitrophenols in the environment.


  • Organizational Affiliation

    Department of Chemistry, North Carolina State University , Raleigh, North Carolina , 27695-8204.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Dehaloperoxidase B
A, B
137Amphitrite ornataMutation(s): 0 
UniProt
Find proteins for Q9NAV7 (Amphitrite ornata)
Explore Q9NAV7 
Go to UniProtKB:  Q9NAV7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9NAV7
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 5 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download Ideal Coordinates CCD File 
C [auth A],
J [auth B]
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
4NC
Query on 4NC

Download Ideal Coordinates CCD File 
F [auth A],
K [auth B]
4-NITROCATECHOL
C6 H5 N O4
XJNPNXSISMKQEX-UHFFFAOYSA-N
SO4
Query on SO4

Download Ideal Coordinates CCD File 
D [auth A],
E [auth A]
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
GOL
Query on GOL

Download Ideal Coordinates CCD File 
H [auth A],
I [auth A],
L [auth B]
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
OXY
Query on OXY

Download Ideal Coordinates CCD File 
G [auth A]OXYGEN MOLECULE
O2
MYMOFIZGZYHOMD-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.98 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.170 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 59.883α = 90
b = 67.192β = 90
c = 67.442γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Science Foundation (NSF, United States)United StatesCHE-1150709

Revision History  (Full details and data files)

  • Version 1.0: 2016-04-27
    Type: Initial release
  • Version 1.1: 2016-06-01
    Changes: Database references
  • Version 1.2: 2017-09-06
    Changes: Author supporting evidence, Database references, Derived calculations
  • Version 1.3: 2019-11-27
    Changes: Author supporting evidence
  • Version 1.4: 2024-03-06
    Changes: Data collection, Database references, Derived calculations