title: Identification and characterization of novel esterases from a deep-sea sediment metagenome.
abstract: A deep-sea sediment metagenomic library was constructed and screened for lipolytic enzymes by activity-based approach. Nine novel lipolytic enzymes were identified, and the amino acid sequences shared 56% to 84% identity to other lipolytic enzymes in the database. Phylogenetic analysis showed that these enzymes belonged to family IV lipolytic enzymes. One of the lipolytic enzymes, Est6, was successfully cloned and expressed in Escherichia coli Rosetta in a soluble form. The recombinant protein was purified by Ni-nitrilotriacetic affinity chromatography column and characterized using p-nitrophenyl esters with various chain lengths. The est6 gene consisted of 909 bp that encoded 302 amino acid residues. Est6 was most similar to a lipolytic enzyme from uncultured bacterium (ACL67845, 61% identity) isolated from the South China Sea marine sediment metagenome. The characterization of Est6 revealed that it was a cold-active esterase and exhibited the highest activity toward p-nitrophenyl butyrate (C4) at 20°C and pH 7.5.
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Xiawei
authors.initials: X
authors.lastname: Jiang
authors.forename: Xuewei
authors.initials: X
authors.lastname: Xu
authors.forename: Yingyi
authors.initials: Y
authors.lastname: Huo
authors.forename: Yuehong
authors.initials: Y
authors.lastname: Wu
authors.forename: Xufen
authors.initials: X
authors.lastname: Zhu
authors.forename: Xinqi
authors.initials: X
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Wu
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D002087:Butyrates; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D004950:Esterases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D015698:Genomic Library; D019015:Geologic Sediments / Q000382:microbiology*; D054892:Metagenome; D008969:Molecular Sequence Data; D009792:Oceans and Seas; D010802:Phylogeny; D012623:Seawater / Q000382:microbiology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity
chemical_list: D002087:Butyrates; C033592:4-nitrophenyl butyrate; D004950:Esterases