title: Insights into the fatty acid chain length specificity of the carboxylesterase PA3859 from Pseudomonas aeruginosa: A combined structural, biochemical and computational study.
abstract: The open reading frame PA3859 of Pseudomonas aeruginosa encodes an intracellular carboxylesterase belonging to a group of microbial enzymes (EC 3.1.1.1) that catalyze the hydrolysis of aliphatic and aromatic esters with a broad substrate specificity. With few exceptions, for this class of enzymes, belonging to the α/β-hydrolase fold superfamily, very little information is available regarding their biochemical activity and in vivo function. The X-ray crystal structure of recombinant PA3859 has been determined for two crystal forms (space groups P2(1) and P2(1)2(1)2). The kinetic properties of the enzyme were studied using p-nitrophenyl esters as substrates and data fitted to a surface dilution mixed micelle kinetic model. Enzymatic assays and computational docking simulations, pinpointed the enzyme's preference for esters of palmitic and/or stearic acids and provided insights into the enzyme-substrate favorable binding modes.
authors.affiliation: Istituto di Cristallografia, Consiglio Nazionale delle Ricerche, Area Science Park - Basovizza, S.S. 14, Km 163.5, I-34149 Trieste, Italy. alessandro.pesaresi@ts.ic.cnr.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Pesaresi
authors.forename: Doriano
authors.initials: D
authors.lastname: Lamba
mesh_terms: D000465:Algorithms; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D055162:Biocatalysis; D043182:Carboxylesterase / Q000737:chemistry / Q000378:metabolism*; D020134:Catalytic Domain; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D009596:Nitrophenols / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D005227:Fatty Acids; D009596:Nitrophenols; D043182:Carboxylesterase; C024836:4-nitrophenol