title: Crystal structure of Proteus mirabilis lipase, a novel lipase from the Proteus/psychrophilic subfamily of lipase family I.1.
abstract: Bacterial lipases from family I.1 and I.2 catalyze the hydrolysis of triacylglycerol between 25-45°C and are used extensively as biocatalysts. The lipase from Proteus mirabilis belongs to the Proteus/psychrophilic subfamily of lipase family I.1 and is a promising catalyst for biodiesel production because it can tolerate high amounts of water in the reaction. Here we present the crystal structure of the Proteus mirabilis lipase, a member of the Proteus/psychrophilic subfamily of I.1lipases. The structure of the Proteus mirabilis lipase was solved in the absence and presence of a bound phosphonate inhibitor. Unexpectedly, both the apo and inhibitor bound forms of P. mirabilis lipase were found to be in a closed conformation. The structure reveals a unique oxyanion hole and a wide active site that is solvent accessible even in the closed conformation. A distinct mechanism for Ca²⁺ coordination may explain how these lipases can fold without specific chaperones.
authors.affiliation: Department of Chemistry and Biochemisty, University of California Los Angeles, Los Angeles, California, United States of America.
authors.forename: Tyler P
authors.initials: TP
authors.lastname: Korman
authors.forename: James U
authors.initials: JU
authors.lastname: Bowie
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry*; D055162:Biocatalysis; D002118:Calcium / Q000737:chemistry; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry; D006860:Hydrogen Bonding; D008049:Lipase / Q000037:antagonists & inhibitors / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D063065:Organophosphonates / Q000737:chemistry; D017433:Protein Structure, Secondary; D011513:Proteus mirabilis / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D004791:Enzyme Inhibitors; D063065:Organophosphonates; D012997:Solvents; D014867:Water; D008049:Lipase; D002118:Calcium