Identification and functional characterisation of genes encoding the omega-3 polyunsaturated fatty acid biosynthetic pathway from the coccolithophore Emiliania huxleyi
Identification and functional characterisation of genes encoding the omega-3 polyunsaturated fatty acid biosynthetic pathway from the coccolithophore Emiliania huxleyi
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DOI：
10.1016/j.phytochem.2011.01.022
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发表时间：
2011-05-01
期刊：
影响因子：
3.8
通讯作者：
Napier, Johnathan A.
中科院分区：
文献类型：
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作者：
Sayanova, Olga;Haslam, Richard P.;Napier, Johnathan A.
原藻科球石藻埃米利亚·赫胥黎是我们海洋中最丰富的藻类之一，因此在海洋食物网中起着核心作用。E. huxleyi以合成和积累omega-3长链多不饱和脂肪酸二十二碳六烯酸（DHA; 22:6 Delta(4,7,10,13,16,19), n-3）而闻名，该脂肪酸积累在鱼油中，已知对人类有益健康，可预防心血管疾病和相关病理。在这里，我们描述了五个赫胥黎基因的鉴定和功能特征，这些基因指导这种藻类合成二十二碳六烯酸。令人惊讶的是，E. huxleyi不使用传统的Delta 6途径，而是使用替代的Delta 8去饱和途径，这种途径以前只在少数不相关的微生物中观察到。鉴于E. huxleyi积累了大量的δ 6-不饱和脂肪酸硬脂酸（18:4 δ (6,9,12,15), n-3），我们推断DHA的生物合成可能是由硬脂酸的合成代谢区隔化的。(C) 2011 Elsevier Ltd.版权所有。
The Prymnesiophyceae coccolithophore Emiliania huxleyi is one of the most abundant alga in our oceans and therefore plays a central role in marine foodwebs. E. huxleyi is notable for the synthesis and accumulation of the omega-3 long chain polyunsaturated fatty acid docosahexaenoic acid (DHA; 22:6 Delta(4,7,10,13,16,19), n-3) which is accumulated in fish oils and known to have health-beneficial properties to humans, preventing cardiovascular disease and related pathologies. Here we describe the identification and functional characterisation of the five E. huxleyi genes which direct the synthesis of docosahexaenoic acid in this alga. Surprisingly, E. huxleyi does not use the conventional Delta 6-pathway, instead using the alternative Delta 8-desaturation route which has previously only been observed in a few unrelated microorganisms. Given that E. huxleyi accumulates significant levels of the Delta 6-desaturated fatty acid stearidonic acid (18:4 Delta(6,9,12,15), n-3), we infer that the biosynthesis of DHA is likely to be metabolically compartmentalised from the synthesis of stearidonic acid. (C) 2011 Elsevier Ltd. All rights reserved.