Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Hetero 4-mer - A2B2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly 2  

 3D View: Structure | Electron Density | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Hetero 4-mer - A2B2 

Biological assembly 2 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 279.50 kDa 
• Atom Count: 20303 
• Residue Count: 2474 
• Unique protein chains: 2

5DWZ

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

• DOI: 10.2210/pdb5DWZ/pdb

• Classification: TRANSFERASE
• Organism(s): Pseudomonas aeruginosa
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2015-09-23 Released: 2016-02-03 
• Deposition Author(s): Drees, S.L., Li, C., Prasetya, F., Saleem, M., Dreveny, I., Hennecke, U., Williams, P., Emsley, J., Fetzner, S.
• Funding Organization(s): German Research Foundation

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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 

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

• PubMed: 26811339 
• 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 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.

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Organizational Affiliation: 

From the Institute for Molecular Microbiology and Biotechnology and [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
3-oxoacyl-[acyl-carrier-protein] synthase 3	C, D, F, H	350	Pseudomonas aeruginosa	Mutation(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

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
3-oxoacyl-(Acyl carrier protein) synthase III	A, B, E, G	283	Pseudomonas aeruginosa	Mutation(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

Small Molecules

Ligands 8 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
MPO	C, D, H	3[N-MORPHOLINO]PROPANE SULFONIC ACID C7 H15 N O4 S DVLFYONBTKHTER-UHFFFAOYSA-N
PGE	B	TRIETHYLENE GLYCOL C6 H14 O4 ZIBGPFATKBEMQZ-UHFFFAOYSA-N
TRS	C	2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL C4 H12 N O3 LENZDBCJOHFCAS-UHFFFAOYSA-O
PEG	D, H	DI(HYDROXYETHYL)ETHER C4 H10 O3 MTHSVFCYNBDYFN-UHFFFAOYSA-N
PO4	A, C, D, E, F, H	PHOSPHATE ION O4 P NBIIXXVUZAFLBC-UHFFFAOYSA-K
GOL	B, C, D	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
CL	C, D	CHLORIDE ION Cl VEXZGXHMUGYJMC-UHFFFAOYSA-M
NA	E	SODIUM ION Na FKNQFGJONOIPTF-UHFFFAOYSA-N

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 = 78.486	α = 90
b = 114.96	β = 90
c = 289.675	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
XDS	data reduction
XDS	data scaling
PHASER	phasing

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2015-09-23 
• Released Date: 2016-02-03 
Deposition Author(s): Drees, S.L., Li, C., Prasetya, F., Saleem, M., Dreveny, I., Hennecke, U., Williams, P., Emsley, J., Fetzner, S.

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Funding Organization	Location	Grant Number
German Research Foundation	Germany	FE 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