5FUS

Crystal structure of B. cenocepacia DfsA

Summary for 5FUS

• Entry DOI: 10.2210/pdb5fus/pdb
• Descriptor: Putative enoyl CoA hydratase, SULFATE ION, GLYCEROL, ... (7 entities in total)
• Functional Keywords: lyase, crotonase, quorum sensing, bdsf biosynthesis
• Biological source: Burkholderia cenocepacia (strain ATCC BAA-245 / DSM 16553 / LMG 16656 / NCTC 13227 / J2315 / CF5610) (Burkholderia cepacia (strain J2315))
• Total number of polymer chains: 3
• Total formula weight: 98024.24

Authors

Spadaro, F.,Scoffone, V.C.,Chiarelli, L.R.,Fumagalli, M.,Buroni, S.,Riccardi, G.,Forneris, F. (deposition date: 2016-01-29, release date: 2016-06-01, Last modification date: 2024-01-10)

Primary citation

Spadaro, F.,Scoffone, V.C.,Chiarelli, L.R.,Fumagalli, M.,Buroni, S.,Riccardi, G.,Forneris, F.
The Crystal Structure of Burkholderia Cenocepacia Dfsa Provides Insights Into Substrate Recognition and Quorum Sensing Fatty Acid Biosynthesis.
Biochemistry, 55:3241-, 2016

PubMed Abstract: Burkholderia cenocepacia is a major concern among respiratory tract infections in cystic fibrosis patients. This pathogen is particularly difficult to treat because of its high level of resistance to the clinically relevant antimicrobial agents. In B. cenocepacia, the quorum sensing cell-cell communication system is involved in different processes that are important for bacterial virulence, such as biofilm formation and protease and siderophore production. Targeting the enzymes involved in this process represents a promising therapeutic approach. With the aim of finding effective quorum sensing inhibitors, we have determined the three-dimensional structure of B. cenocepacia diffusible factor synthase A, DfsA. This bifunctional crotonase (dehydratase/thioesterase) produces the characteristic quorum sensing molecule of B. cenocepacia, cis-2-dodecenoic acid or BDSF, starting from 3-hydroxydodecanoyl-acyl carrier protein. Unexpectedly, the crystal structure revealed the presence of a lipid molecule in the catalytic site of the enzyme, which was identified as dodecanoic acid. Our biochemical characterization shows that DfsA is able to use dodecanoyl-acyl carrier protein as a substrate, demonstrating that dodecanoic acid, the product of this reaction, is released very slowly from the DfsA active site, therefore acting as a DfsA inhibitor. This molecule shows an unprecedented conformational arrangement inside the DfsA active site. In contrast with previous hypotheses, our data illustrate how DfsA and closely related homologous enzymes can recognize long hydrophobic substrates without large conformational changes or assistance by additional regulator molecules. The elucidation of the substrate binding mode in DfsA provides the starting point for structure-based drug discovery studies targeting B. cenocepacia quorum sensing-assisted virulence.

PubMed: 27198181
DOI: 10.1021/ACS.BIOCHEM.6B00178

Experimental method

X-RAY DIFFRACTION (1.87 Å)