1JXZ

Structure of the H90Q mutant of 4-Chlorobenzoyl-Coenzyme A Dehalogenase complexed with 4-hydroxybenzoyl-Coenzyme A (product)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Work: 0.195 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Histidine 90 Function in 4-chlorobenzoyl-coenzyme A Dehalogenase Catalysis

Zhang, W.Wei, Y.Luo, L.Taylor, K.L.Yang, G.Dunaway-Mariano, D.Benning, M.M.Holden, H.M.

(2001) Biochemistry 40: 13474-13482


  • PubMed Abstract: 
  • 4-chlorobenzoyl-coenzyme A (4-CBA-CoA) dehalogenase catalyzes the hydrolytic dehalogenation of 4-CBA-CoA by attack of Asp145 on the C4 of the substrate benzoyl ring to form a Meisenheimer intermediate (EMc), followed by expulsion of chloride ion to f ...

    4-chlorobenzoyl-coenzyme A (4-CBA-CoA) dehalogenase catalyzes the hydrolytic dehalogenation of 4-CBA-CoA by attack of Asp145 on the C4 of the substrate benzoyl ring to form a Meisenheimer intermediate (EMc), followed by expulsion of chloride ion to form an arylated enzyme intermediate (EAr) and, finally, ester hydrolysis in EAr to form 4-hydroxybenzoyl-CoA (4-HBA-CoA). This study examines the contribution of the active site His90 to catalysis of this reaction pathway. The His90 residue was replaced with glutamine by site-directed mutagenesis. X-ray crystallographic analysis of H90Q dehalogenase complexed with 4-HBA-CoA revealed that the positions of the catalytic groups are unchanged from those observed in the structure of the 4-HBA-CoA-wild-type dehalogenase complex. The one exception is the Gln90 side chain, which is rotated away from the position of the His90 side chain. The vacated His90 site is occupied by two water molecules. Kinetic techniques were used to evaluate ligand binding and catalytic turnover rates in the wild-type and H90Q mutant dehalogenases. The rate constants for 4-CBA-CoA (both 7 microM(-1) x s(-1)) and 4-HBA-CoA (33 and 11 microM(-1) x s(-1)) binding to the two dehalogenases are similar in value. For wild-type dehalogenase, the rate constant for a single turnover is 2.3 s(-1) while that for multiple turnovers is 0.7 s(-1). For H90Q dehalogenase, these rate constants are 1.6 x 10(-2) and 2 x 10(-4) s(-1). The rate constants for EMc formation in wild-type and mutant dehalogenase are approximately 200 s(-1) while the rate constants for EAr formation are 40 and 0.3 s(-1), respectively. The rate constant for hydrolysis of EAr in wild-type dehalogenase is 20 s(-1) and in the H90Q mutant, 0.13 s(-1). The 133-fold reduction in the rate of EAr formation in the mutant may be the result of active site hydration, while the 154-fold reduction in the rate EAr hydrolysis may be the result of lost general base catalysis. Substitution of the His90 with Gln also introduces a rate-limiting step which follows catalysis, and may involve renewing the catalytic site through a slow conformational change.


    Organizational Affiliation

    Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
4-chlorobenzoyl Coenzyme A dehalogenase
A, B, C
269Pseudomonas sp. (strain CBS-3)EC: 3.8.1.7
Find proteins for A5JTM5 (Pseudomonas sp. (strain CBS-3))
Go to UniProtKB:  A5JTM5
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download SDF File 
Download CCD File 
B
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
CA
Query on CA

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Download CCD File 
A, B, C
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
BCA
Query on BCA

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Download CCD File 
A, B, C
4-HYDROXYBENZOYL COENZYME A
C28 H40 N7 O18 P3 S
LTVXPVBFJBTNIJ-TYHXJLICSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Work: 0.195 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 108.100α = 90.00
b = 102.700β = 90.00
c = 90.700γ = 90.00
Software Package:
Software NamePurpose
FRAMBOdata collection
XDSdata reduction
XDSdata scaling
TNTrefinement
TNTphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-10-03
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-04
    Type: Refinement description
  • Version 1.4: 2018-01-31
    Type: Data collection