5DWZ

Structural and functional characterization of PqsBC, a condensing enzyme in the biosynthesis of the Pseudomonas aeruginosa quinolone signal


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.04 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.192 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

PqsBC, a Condensing Enzyme in the Biosynthesis of the Pseudomonas aeruginosa Quinolone Signal: CRYSTAL STRUCTURE, INHIBITION, AND REACTION MECHANISM.

Drees, S.L.Li, C.Prasetya, F.Saleem, M.Dreveny, I.Williams, P.Hennecke, U.Emsley, J.Fetzner, S.

(2016) J Biol Chem 291: 6610-6624

  • DOI: 10.1074/jbc.M115.708453
  • Primary Citation of Related Structures:  
    5DWZ

  • PubMed Abstract: 
  • Pseudomonas aeruginosaproduces a number of alkylquinolone-type secondary metabolites best known for their antimicrobial effects and involvement in cell-cell communication. In the alkylquinolone biosynthetic pathway, the β-ketoacyl-(acyl carrier prote ...

    Pseudomonas aeruginosaproduces a number of alkylquinolone-type secondary metabolites best known for their antimicrobial effects and involvement in cell-cell communication. In the alkylquinolone biosynthetic pathway, the β-ketoacyl-(acyl carrier protein) synthase III (FabH)-like enzyme PqsBC catalyzes the condensation of octanoyl-coenzyme A and 2-aminobenzoylacetate (2-ABA) to form the signal molecule 2-heptyl-4(1H)-quinolone. PqsBC, a potential drug target, is unique for its heterodimeric arrangement and an active site different from that of canonical FabH-like enzymes. Considering the sequence dissimilarity between the subunits, a key question was how the two subunits are organized with respect to the active site. In this study, the PqsBC structure was determined to a 2 Å resolution, revealing that PqsB and PqsC have a pseudo-2-fold symmetry that unexpectedly mimics the FabH homodimer. PqsC has an active site composed of Cys-129 and His-269, and the surrounding active site cleft is hydrophobic in character and approximately twice the volume of related FabH enzymes that may be a requirement to accommodate the aromatic substrate 2-ABA. From physiological and kinetic studies, we identified 2-aminoacetophenone as a pathway-inherent competitive inhibitor of PqsBC, whose fluorescence properties could be used forin vitrobinding studies. In a time-resolved setup, we demonstrated that the catalytic histidine is not involved in acyl-enzyme formation, but contributes to an acylation-dependent increase in affinity for the second substrate 2-ABA. Introduction of Asn into the PqsC active site led to significant activity toward the desamino substrate analog benzoylacetate, suggesting that the substrate 2-ABA itself supplies the asparagine-equivalent amino function that assists in catalysis.


    Organizational Affiliation

    From the Institute for Molecular Microbiology and Biotechnology and fetzner@uni-muenster.de.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
3-oxoacyl-[acyl-carrier-protein] synthase 3CDFH350Pseudomonas aeruginosaMutation(s): 1 
Gene Names: pqsC
EC: 2.3.1.180 (PDB Primary Data), 2.3.1.230 (UniProt)
Find proteins for Q9I4X1 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Explore Q9I4X1 
Go to UniProtKB:  Q9I4X1
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
3-oxoacyl-(Acyl carrier protein) synthase IIIABEG283Pseudomonas aeruginosaMutation(s): 0 
Gene Names: pqsB
Find proteins for Q9I4X2 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Explore Q9I4X2 
Go to UniProtKB:  Q9I4X2
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 8 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MPO
Query on MPO

Download Ideal Coordinates CCD File 
C, D, H
3[N-MORPHOLINO]PROPANE SULFONIC ACID
C7 H15 N O4 S
DVLFYONBTKHTER-UHFFFAOYSA-N
 Ligand Interaction
PGE
Query on PGE

Download Ideal Coordinates CCD File 
B
TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N
 Ligand Interaction
TRS
Query on TRS

Download Ideal Coordinates CCD File 
C
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
PEG
Query on PEG

Download Ideal Coordinates CCD File 
D, H
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
PO4
Query on PO4

Download Ideal Coordinates CCD File 
A, C, D, E, F, H
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
GOL
Query on GOL

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B, C, D
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

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C, D
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
NA
Query on NA

Download Ideal Coordinates CCD File 
E
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.04 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.192 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.486α = 90
b = 114.96β = 90
c = 289.675γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
German Research FoundationGermanyFE 383/23-1

Revision History 

  • Version 1.0: 2016-02-03
    Type: Initial release
  • Version 1.1: 2016-02-10
    Changes: Database references
  • Version 1.2: 2016-04-06
    Changes: Database references
  • Version 1.3: 2016-05-11
    Changes: Source and taxonomy
  • Version 1.4: 2017-09-06
    Changes: Advisory, Author supporting evidence