The cold-active lipase of Pseudomonas fragi. Heterologous expression, biochemical characterization and molecular modeling.
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.
Alquati
Claudia
C
Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy.
De Gioia
Luca
L
Santarossa
Gianluca
G
Alberghina
Lilia
L
Fantucci
Piercarlo
P
Lotti
Marina
M
D000595:Amino Acid Sequence; D003080:Cold Temperature; D008049:Lipase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011549:Pseudomonas / Q000201:enzymology*; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014280:Triglycerides / Q000378:metabolism
D014280:Triglycerides; D008049:Lipase