title: Identification and functional characterization of two Δ12-fatty acid desaturases associated with essential linoleic acid biosynthesis in Physcomitrella patens.
abstract: Two Δ(12)-desaturases associated with the primary steps of long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis were successfully cloned from Physcomitrella patens and their functions identified. The open reading frames (ORFs) of PpFAD2-1 and PpFAD2-2 consisted of 1,128 bp and code for 375 amino acids. Their deduced polypeptides showed 62-64 % identity to microsomal Δ(12)-desaturases from other higher plants, and each contained the three histidine clusters typical of the catalytic domains of such enzymes. Yeast cells transformed with plasmid constructs containing PpFAD2-1 or PpFAD2-2 produced an appreciable amount of hexadecadienoic (16:2 Δ(9,12)) and linoleic acids (18:2 Δ(9,12)), not normally present in wild-type yeast cells, indicating that the genes encoded functional Δ(12)-desaturase enzymes. In addition, reduction of the growth temperature from 30 to 15 °C resulted in increased accumulation of unsaturated fatty acid products.
authors.affiliation: Marine Natural Products Research Unit, Department of Pharmacognosy and Pharmaceutical Botany, Faculty of Pharmaceutical Sciences, Prince of Songkla University, Songkhla, 90112, Thailand.
authors.forename: Pichit
authors.initials: P
authors.lastname: Chodok
authors.forename: Pradinunt
authors.initials: P
authors.lastname: Eiamsa-ard
authors.forename: David J
authors.initials: DJ
authors.lastname: Cove
authors.forename: Ralph S
authors.initials: RS
authors.lastname: Quatrano
authors.forename: Sireewan
authors.initials: S
authors.lastname: Kaewsuwan
mesh_terms: D000595:Amino Acid Sequence; D019068:Bryopsida / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D044943:Fatty Acid Desaturases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis; D019787:Linoleic Acid / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D017386:Sequence Homology, Amino Acid
chemical_list: D005231:Fatty Acids, Unsaturated; D019787:Linoleic Acid; D044943:Fatty Acid Desaturases; C040448:delta-12 fatty acid desaturase