1IUX

P-HYDROXYBENZOATE HYDROXYLASE COMPLEXED WITH 4-4-HYDROXYBENZOATE AT PH 9.4


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Work: 0.173 
  • R-Value Observed: 0.173 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

pH-dependent structural changes in the active site of p-hydroxybenzoate hydroxylase point to the importance of proton and water movements during catalysis.

Gatti, D.L.Entsch, B.Ballou, D.P.Ludwig, M.L.

(1996) Biochemistry 35: 567-578

  • DOI: https://doi.org/10.1021/bi951344i
  • Primary Citation of Related Structures:  
    1IUS, 1IUT, 1IUU, 1IUV, 1IUW, 1IUX

  • PubMed Abstract: 

    Deprotonation of p-hydroxybenzoate to the phenolate and reprotonation of the hydroxylated dienone intermediate to form the product are essential steps in the reaction catalyzed by p-hydroxybenzoate hydroxylase (PHBH). The mechanism by which protons are transferred in these reactions is not obvious, because the substrate bound in the active site is isolated from solvent. Structure analyses of wild-type and mutant PHBH, with bound p-hydroxybenzoate or p-aminobenzoate, reveal a chain of proton donors and acceptors (the hydroxyl groups of Tyr201 and Tyr385, and two water molecules) that can connect the substrate 4-OH to His72, a surface residue. This chain could provide a pathway for proton transfer to and from the substrate. Using various combinations of pH and substrates, we show that in crystalline PHBH ionizable groups in the chain may rotate and change hydrogen-bond orientation. Molecular dynamics simulations have been used to predict the preferred orientation of hydrogen bonds in the chain as a function of the ionization states of substrate and His72. The calculations suggest that changes in the ionization state of the substrate could be associated with changes in orientation of the hydrogen bonds in the chain. Transfer of water between the chain of proton donors and the solvent also appears to be an essential part of the mechanism that provides reversible transfer of protons during the hydroxylation reaction.


  • Organizational Affiliation

    Department of Biological Chemistry, University of Michigan, Ann Arbor 48109, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
P-HYDROXYBENZOATE HYDROXYLASE394Pseudomonas aeruginosa PAO1Mutation(s): 0 
Gene Names: POBA
EC: 1.14.13.2
UniProt
Find proteins for P20586 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Explore P20586 
Go to UniProtKB:  P20586
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP20586
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
FAD
Query on FAD

Download Ideal Coordinates CCD File 
B [auth A]FLAVIN-ADENINE DINUCLEOTIDE
C27 H33 N9 O15 P2
VWWQXMAJTJZDQX-UYBVJOGSSA-N
PHB
Query on PHB

Download Ideal Coordinates CCD File 
C [auth A]P-HYDROXYBENZOIC ACID
C7 H6 O3
FJKROLUGYXJWQN-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Work: 0.173 
  • R-Value Observed: 0.173 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 71.73α = 90
b = 146.37β = 90
c = 88.05γ = 90
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
SDMSdata reduction
SDMSdata scaling
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1996-07-11
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Source and taxonomy, Version format compliance
  • Version 1.3: 2017-11-29
    Changes: Derived calculations, Other
  • Version 1.4: 2024-02-07
    Changes: Data collection, Database references, Derived calculations