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A recombinant lipase cloned from Pseudomonas fragi strain IFO 3458 (PFL) was found to retain significant activity at low temperature. In an attempt to elucidate the structural basis of this behaviour, a model of its three-dimensional structure was built by homology and compared with homologous mesophilic lipases, i.e. the Pseudomonas aeruginosa lipase (45% sequence identity) and Burkholderia cepacia lipase (38%). | Eur. J. Biochem. 269 3321-3328 2002 FEBS 2002 doi 10.1046 j.1432-1033.2002.03012.x The cold-active lipase of Pseudomonas fragi Heterologous expression biochemical characterization and molecular modeling Claudia Alquati Luca De Gioia Gianluca Santarossa Lilia Alberghina Piercarlo Fantucci and Marina Lotti Dipartimento di Biotecnologie e Bioscienze Universitci degli Studi di Milano-Bicocca Milano Italy A recombinant lipase cloned from Pseudomonas fragi strain IFO 3458 PFL was found to retain significant activity at low temperature. In an attempt to elucidate the structural basis of this behaviour a model of its three-dimensional structure was built by homology and compared with homologous mesophilic lipases i.e. the Pseudomonas aeruginosa lipase 45 sequence identity and Burkholderia cepacia lipase 38 . In this model features common to all known lipases have been identified such as the catalytic triad S83 D238 and H260 and the oxyanion hole L17 Q84 . Structural modifications recurrent in cold-adaptation i.e. a large amount of charged residues exposed at the protein surface have been detected. Noteworthy is the lack of a disulphide bridge conserved in homologous Pseudomonas lipases that may contribute to increased conformational flexibility of the cold-active enzyme. Keywords lipase Pseudomonas cold-active enzymes modeling selectivity. Enzymes from psychrotrophic and psychrophilic microorganisms have recently received increasing attention due to their relevance for both basic and applied research. This effort has been stimulated by the recognition that cold-adapted enzymes might offer novel opportunities for biotechnological exploitation based on their high catalytic activity at low temperatures low thermostability and unusual specificities. These properties are of interest in different fields such as detergents textile and food industry bioremediation and biocatalysis under low water conditions 1 2 . Furthermore fundamental issues concerning the molecular basis of .
