title: Identification and characterization of a novel bifunctional Δ(12)/Δ(15)-fatty acid desaturase gene from Rhodosporidium kratochvilovae.
abstract: OBJECTIVE
  To elucidate the biosynthesis pathway of linoleic acid and α-linolenic acid in Rhodosporidium kratochvilovae YM25235 and investigate the correlation of polyunsaturated fatty acids with its cold adaptation.
  
  
  RESULTS
  A 1341 bp cDNA sequence, designated as RKD12, putatively encoding a Δ(12)-desaturase was isolated from YM25235. Sequence analysis indicated that this sequence comprised a complete ORF encoding 446 amino acids of 50.6 kDa. The encoded amino acid sequence shared higher similarity to known fungal Δ(12)-desaturases that are characteristic of three conserved histidine-rich motifs. RKD12 was further transformed into Saccharomyces cerevisiae INVScl for functional characterization. Fatty acid analysis showed the yeast transformants accumulated two new fatty acids: linoleic acid and α-linolenic acid. Furthermore, mRNA expression level of RKD12 and the content of linoleic acid and α-linolenic acid were increased significantly with the culture temperature downshift from 30 to 15 °C, which might be helpful for the cold adaptation of YM25235.
  
  
  CONCLUSIONS
  RKD12 is a novel bifunctional ∆(12)/∆(15)-desaturase gene, and the increased RKD12 mRNA expression level and PUFAs content at low temperature might be helpful for the cold adaptation of YM25235.
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, China.
authors.forename: Jinjin
authors.initials: J
authors.lastname: Cui
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, China.
authors.forename: Shiwu
authors.initials: S
authors.lastname: He
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, China.
authors.forename: Xiuling
authors.initials: X
authors.lastname: Ji
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, China.
authors.forename: Lianbing
authors.initials: L
authors.lastname: Lin
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, China.
authors.forename: Yunlin
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Faculty of Life Science and Technology, Kunming University of Science and Technology, 727 South Jingming Road, Kunming, 650500, China. qzhang37@gmail.com.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D003080:Cold Temperature; D044943:Fatty Acid Desaturases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D010802:Phylogeny; D012246:Rhodospirillum / Q000201:enzymology* / Q000378:metabolism / Q000502:physiology; D013379:Substrate Specificity; D017962:alpha-Linolenic Acid / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D017962:alpha-Linolenic Acid; D044943:Fatty Acid Desaturases
keywords: Cold adaptation; Polyunsaturated fatty acids; Rhodosporidium kratochvilovae; Substrate specificity; Δ12-Fatty acid desaturase; Δ15-Fatty acid desaturase