title: Identification and molecular modeling of a novel lipase from an Antarctic soil metagenomic library.
abstract: In this work, we present the construction of a metagenomic library in Escherichia coli using pUC19 vector and environmental DNA directly isolated from Antarctic topsoil and screened for lipolytic enzymes. Screening on agar supplemented with olive oil and rhodamine B revealed one clone with lipolytic activity (Lip1) out of 1000 E. coli clones. This clone harbored a plasmid, pLip1, which has an insert of 4722 bp that was completely sequenced from both directions. Further analysis of the insert showed three open reading frames (ORFs). ORF2 encoded a protein (Lip1 ) of 469 amino acids with 93% identity to the uncultured Pseudomonas sp. lipase LipJ03. Amino acid sequence comparison and phylogenetic analysis indicated that Lip1 lipase was closely related to family I subfamily 3. Furthermore, we present a three-dimensional model of lipase Lip1 which was generated based on the two known structures of mesophilic lipases from Pseudomonas sp. MIS 38 (PML lipase, PDB; 2Z8X) and Serratia marcescens (SML lipase, PDB: 2QUB). Finally, we report the results of comparisons between lipase Lip1 and mesophilic lipases and point out similarities and differences in the catalytic site and in other parts of the analyzed structures.
authors.affiliation: Department of Microbiology, Chemical Faculty, Gdańsk University of Technology, Gdańsk, Poland. hcieslin@pg.gda.pl
authors.forename: Hubert
authors.initials: H
authors.lastname: Cieśliński
authors.forename: Aneta
authors.initials: A
authors.lastname: Białkowskaa
authors.forename: Karolina
authors.initials: K
authors.lastname: Tkaczuk
authors.forename: Anna
authors.initials: A
authors.lastname: Długołecka
authors.forename: Józef
authors.initials: J
authors.lastname: Kur
authors.forename: Marianna
authors.initials: M
authors.lastname: Turkiewicz
mesh_terms: D000595:Amino Acid Sequence; D000864:Antarctic Regions; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D015723:Gene Library; D023281:Genomics; D008049:Lipase / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D008049:Lipase