title: Functional identification and regulatory analysis of Δ6-fatty acid desaturase from the oleaginous fungus Mucor sp. EIM-10.
abstract: OBJECTIVE
  To enlarge the diversity of the desaturases associated with PUFA biosynthesis and to better understand the transcriptional regulation of desaturases, a Δ6-desaturase gene (Md6) from Mucor sp. and its 5'-upstream sequence was functionally identified in Saccharomyces cerevisiae.
  
  
  RESULTS
  Expression of the Δ6-fatty acid desaturase (Md6) in S. cerevisiae showed that Md6 could convert linolenic acid to γ-linolenic acid. Computational analysis of the promoter of Md6 suggested it contains several eukaryotic fundamental transcription regulatory elements. In vivo functional analysis of the promoter showed the 5'-upstream sequence of Md6 could initiate expression of GFP and Md6 itself in S. cerevisiae. A series deletion analysis of the promoter suggested that sequence between -919 to -784 bp (relative to start site) named as eMd6 is the key factor for high activity of Δ6-desaturase. The activity of Δ6-desaturase was increased by 2.8-fold and 2.5-fold when the eMd6 sequence was placed upstream of -434 with forward or reverse orientations respectively.
  
  
  CONCLUSIONS
  To our best knowledge, the native promoter of Md6 from Mucor is the strongest promoter for Δ6-desaturase reported so far and the sequence between -919 to -784 bp is an enhancer for Δ6-desaturase activity.
authors.affiliation: Engineering Research Center of Industrial Microbiology, College of Life Sciences, Fujian Normal University, Shangjie Town, Minhou District, Fuzhou, 350117, Fujian, People's Republic of China.
authors.forename: Xianzhang
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Engineering Research Center of Industrial Microbiology, College of Life Sciences, Fujian Normal University, Shangjie Town, Minhou District, Fuzhou, 350117, Fujian, People's Republic of China.
authors.forename: Hongjiao
authors.initials: H
authors.lastname: Liu
authors.affiliation: Engineering Research Center of Industrial Microbiology, College of Life Sciences, Fujian Normal University, Shangjie Town, Minhou District, Fuzhou, 350117, Fujian, People's Republic of China.
authors.forename: Yongchao
authors.initials: Y
authors.lastname: Niu
authors.affiliation: Engineering Research Center of Industrial Microbiology, College of Life Sciences, Fujian Normal University, Shangjie Town, Minhou District, Fuzhou, 350117, Fujian, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qi
authors.affiliation: Engineering Research Center of Industrial Microbiology, College of Life Sciences, Fujian Normal University, Shangjie Town, Minhou District, Fuzhou, 350117, Fujian, People's Republic of China.
authors.forename: Mingliang
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Engineering Research Center of Industrial Microbiology, College of Life Sciences, Fujian Normal University, Shangjie Town, Minhou District, Fuzhou, 350117, Fujian, People's Republic of China. hjz@fjnu.edu.cn.
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Huang
mesh_terms: D001483:Base Sequence; D002849:Chromatography, Gas; D004742:Enhancer Elements, Genetic / Q000235:genetics; D004952:Esters / Q000032:analysis; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D050602:Linoleoyl-CoA Desaturase / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D009089:Mucor / Q000201:enzymology* / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion
chemical_list: D004952:Esters; D050602:Linoleoyl-CoA Desaturase
keywords: Desaturase; Enhancer; Mucor; Polyunsaturated fatty acid; Promoter; γ-linolenic acid