title: Characterization of a Soil Metagenome-Derived Gene Encoding Wax Ester Synthase.
abstract: A soil metagenome contains the genomes of all microbes included in a soil sample, including those that cannot be cultured. In this study, soil metagenome libraries were searched for microbial genes exhibiting lipolytic activity and those involved in potential lipid metabolism that could yield valuable products in microorganisms. One of the subclones derived from the original fosmid clone, pELP120, was selected for further analysis. A subclone spanning a 3.3 kb DNA fragment was found to encode for lipase/esterase and contained an additional partial open reading frame encoding a wax ester synthase (WES) motif. Consequently, both pELP120 and the full length of the gene potentially encoding WES were sequenced. To determine if the wes gene encoded a functioning WES protein that produced wax esters, gas chromatography-mass spectroscopy was conducted using ethyl acetate extract from an Escherichia coli strain that expressed the wes gene and was grown with hexadecanol. The ethyl acetate extract from this E. coli strain did indeed produce wax ester compounds of various carbon-chain lengths. DNA sequence analysis of the full-length gene revealed that the gene cluster may be derived from a member of Proteobacteria, whereas the clone does not contain any clear phylogenetic markers. These results suggest that the wes gene discovered in this study encodes a functional protein in E. coli and produces wax esters through a heterologous expression system.
authors.affiliation: Department of Applied Bioscience, Dong-A University, Busan 49315, Republic of Korea.
authors.forename: Nam Hee
authors.initials: NH
authors.lastname: Kim
authors.affiliation: Department of Applied Bioscience, Dong-A University, Busan 49315, Republic of Korea.
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Applied Bioscience, Dong-A University, Busan 49315, Republic of Korea.
authors.forename: Eunsook
authors.initials: E
authors.lastname: Chung
authors.affiliation: Department of Applied Bioscience, Dong-A University, Busan 49315, Republic of Korea.
authors.forename: Hyun-Ah
authors.initials: HA
authors.lastname: So
authors.affiliation: Department of Applied Bioscience, Dong-A University, Busan 49315, Republic of Korea.
authors.forename: Myung Hwan
authors.initials: MH
authors.lastname: Lee
authors.affiliation: Department of Agricultural Chemistry, Chonnam National University, Gwangju 61186, Republic of Korea.
authors.forename: Jin-Cheol
authors.initials: JC
authors.lastname: Kim
authors.affiliation: Department of Applied Bioscience, Dong-A University, Busan 49315, Republic of Korea.
authors.forename: Eul Chul
authors.initials: EC
authors.lastname: Hwang
authors.affiliation: Department of Applied Bioscience, Dong-A University, Busan 49315, Republic of Korea.
authors.forename: Seon-Woo
authors.initials: SW
authors.lastname: Lee
mesh_terms: D000217:Acyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001483:Base Sequence; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D004950:Esterases / Q000235:genetics; D005798:Genes, Bacterial; D015698:Genomic Library; D008049:Lipase / Q000378:metabolism*; D050356:Lipid Metabolism / Q000235:genetics; D054892:Metagenome; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013379:Substrate Specificity
chemical_list: D000217:Acyltransferases; C079165:long-chain-alcohol O-fatty-acyltransferase; D004950:Esterases; D008049:Lipase
keywords: Lipid metabolism; soil metagenome; wax ester synthase; wes