Details

Autor(en) / Beteiligte

• Xue, Zhixiong
• He, Hongxian
• Hollerbach, Dieter
• Macool, Daniel J
• Yadav, Narendra S
• Zhang, Hongxiang
• Szostek, Bogdan
• Zhu, Quinn

Titel

Identification and characterization of new [Delta]-17 fatty acid desaturases

Ist Teil von

• Applied microbiology and biotechnology, 2013-03, Vol.97 (5), p.1973

Ort / Verlag

Heidelberg: Springer Nature B.V

Erscheinungsjahr

2013

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [omega]-3 fatty acid desaturase is a key enzyme for the biosynthesis of [omega]-3 polyunsaturated fatty acids via the oxidative desaturase/elongase pathways. Here we report the identification of three [omega]-3 desaturases from oomycetes, Pythium aphanidermatum, Phytophthora sojae, and Phytophthora ramorum. These new [omega]-3 desaturases share 55 % identity at the amino acid level with the known [Delta]-17 desaturase of Saprolegnia diclina, and about 31 % identity with the bifunctional [Delta]-12/[Delta]-15 desaturase of Fusarium monoliforme. The three enzymes were expressed in either wild-type or codon optimized form in an engineered arachidonic acid producing strain of Yarrowia lipolytica to study their activity and substrate specificity. All three were able to convert the [omega]-6 arachidonic acid to the [omega]-3 eicosapentanoic acid, with a substrate conversion efficiency of 54-65 %. These enzymes have a broad [omega]-6 fatty acid substrate spectrum, including both C18 and C20 [omega]-6 fatty acids although they prefer the C20 substrates, and have strong [Delta]-17 desaturase activity but weaker [Delta]-15 desaturase activity. Thus, they belong to the [Delta]-17 desaturase class. Unlike the previously identified bifunctional [Delta]-12/[Delta]-15 desaturase from F. monoliforme, they lack [Delta]-12 desaturase activity. The newly identified [Delta]-17 desaturases could use fatty acids in both acyl-CoA and phospholipid fraction as substrates. The identification of these [Delta]-17 desaturases provides a set of powerful new tools for genetic engineering of microbes and plants to produce [omega]-3 fatty acids, such as eicosapentanoic acid and docosahexanoic acid, at high levels.[PUBLICATION ABSTRACT]