title: FadD from Pseudomonas putida CA-3 is a true long-chain fatty acyl coenzyme A synthetase that activates phenylalkanoic and alkanoic acids.
abstract: A fatty acyl coenzyme A synthetase (FadD) from Pseudomonas putida CA-3 is capable of activating a wide range of phenylalkanoic and alkanoic acids. It exhibits the highest rates of reaction and catalytic efficiency with long-chain aromatic and aliphatic substrates. FadD exhibits higher k(cat) and K(m) values for aromatic substrates than for the aliphatic equivalents (e.g., 15-phenylpentadecanoic acid versus pentadecanoic acid). FadD is inhibited noncompetitively by both acrylic acid and 2-bromooctanoic acid. The deletion of the fadD gene from P. putida CA-3 resulted in no detectable growth or polyhydroxyalkanoate (PHA) accumulation with 10-phenyldecanoic acid, decanoic acid, and longer-chain substrates. The results suggest that FadD is solely responsible for the activation of long-chain phenylalkanoic and alkanoic acids. While the CA-3DeltafadD mutant could grow on medium-chain substrates, a decrease in growth yield and PHA accumulation was observed. The PHA accumulated by CA-3DeltafadD contained a greater proportion of short-chain monomers than did wild-type PHA. Growth of CA-3DeltafadD was unaffected, but PHA accumulation decreased modestly with shorter-chain substrates. The complemented mutant regained 70% to 90% of the growth and PHA-accumulating ability of the wild-type strain depending on the substrate. The expression of an extra copy of fadD in P. putida CA-3 resulted in increased levels of PHA accumulation (up to 1.6-fold) and an increase in the incorporation of longer-monomer units into the PHA polymer.
authors.affiliation: School of Biomolecular and Biomedical Science, Ardmore House, and Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland. kevin.oconnor@ucd.ie.
authors.forename: Aisling R
authors.initials: AR
authors.lastname: Hume
authors.forename: Jasmina
authors.initials: J
authors.lastname: Nikodinovic-Runic
authors.forename: Kevin E
authors.initials: KE
authors.lastname: O'Connor
mesh_terms: D000179:Acrylates / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002210:Caprylates / Q000494:pharmacology; D003066:Coenzyme A Ligases / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005227:Fatty Acids / Q000378:metabolism*; D017353:Gene Deletion; D018628:Gene Dosage; D007700:Kinetics; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D054813:Polyhydroxyalkanoates / Q000378:metabolism; D016958:Pseudomonas putida / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D000179:Acrylates; D001426:Bacterial Proteins; D002210:Caprylates; D003470:Culture Media; D004791:Enzyme Inhibitors; D005227:Fatty Acids; D054813:Polyhydroxyalkanoates; C019279:2-bromooctanoic acid; D003066:Coenzyme A Ligases; C036658:acrylic acid