title: Molecular cloning and functional characterization of a Δ6-fatty acid desaturase gene from Rhizopus oryzae.
abstract: The objective was to screen for and isolate a novel enzyme with the specific activity of a Δ6-fatty acid desaturase from Rhizopus oryzae. In this study, R. oryzae was identified as a novel fungal species that produces large amounts of γ-linolenic acid. A full-length cDNA, designated here as RoD6D, with high homology to fungal Δ6-fatty acid desaturase genes was isolated from R. oryzae by using the rapid amplification of cDNA ends method. It had an open reading frame of 1176 bp encoding a deduced polypeptide of 391 amino acids. Bioinformatics analysis characterized the putative RoD6D protein as a typical membrane-bound desaturase, including three conserved histidine-rich motifs, a hydropathy profile, and a cytochrome b5 -like domain in the N terminus. When the coding sequence was expressed in the Saccharomyces cerevisiae strain INVScl, the encoded product of RoD6D exhibited Δ6-fatty acid desaturase activity that led to the accumulation of γ-linolenic acid. The corresponding genomic sequence of RoD6D was 1565 bp in length, with five introns. This is the first report on the characterization and gene cloning of a Δ6-fatty acid desaturase of R. oryzae from Douchi.
authors.affiliation: Department of Immunology, Chong Qing Medical University, Chongqing, 400016, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhu
authors.forename: Bi-Bo
authors.initials: BB
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D016000:Cluster Analysis; D015870:Gene Expression; D015723:Gene Library; D007438:Introns; D050602:Linoleoyl-CoA Desaturase / Q000235:genetics* / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012233:Rhizopus / Q000201:enzymology* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D017965:gamma-Linolenic Acid / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D017965:gamma-Linolenic Acid; D050602:Linoleoyl-CoA Desaturase