Identification of primula fatty acid delta 6-desaturases with n-3 substrate preferences.
Fatty acid Delta(6)-desaturation, the first committed step in C(20) polyunsaturated fatty acid biosynthesis, is generally considered not to discriminate between n-3 and n-6 substrates. We previously identified higher plant species that showed preferential Delta(6)-desaturation of n-3 C(18) fatty acid substrates. A polymerase chain reaction-based approach was used to isolate 'front-end' cytochrome b(5) fusion desaturases from Primula vialii Franchet and Primula farinosa L. Functional analysis in Saccharomyces cerevisiae identified fatty acid Delta(6)-desaturases with a strong specificity for the n-3 substrate alpha-linolenic acid (18:3 Delta(9,12,15)). These results indicate that the accumulation of octadecatetraenoic acid (18:4 Delta(6,9,12,15)) in planta is due to the activity of a novel n-3-specific fatty acid Delta(6)-desaturase.
Long Ashton Research Station, Long Ashton, Bristol BS41 9AF, UK. olga.sayanova@bbsrc.ac.uk
Olga V
OV
Sayanova
Frédéric
F
Beaudoin
Louise V
LV
Michaelson
Peter R
PR
Shewry
Johnathan A
JA
Napier
D000595:Amino Acid Sequence; D019677:Artificial Gene Fusion; D015786:Cytochromes b5 / Q000235:genetics / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000378:metabolism*; D050602:Linoleoyl-CoA Desaturase; D008969:Molecular Sequence Data; D031825:Primula / Q000201:enzymology*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity
D015525:Fatty Acids, Omega-3; D015786:Cytochromes b5; D044943:Fatty Acid Desaturases; D050602:Linoleoyl-CoA Desaturase