A novel fungal ω3-desaturase with wide substrate specificity from arachidonic acid-producing Mortierella alpina 1S-4
A novel fungal ω3-desaturase with wide substrate specificity from arachidonic acid-producing Mortierella alpina 1S-4
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DOI：
10.1007/s00253-004-1760-x
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发表时间：
2005-03-01
影响因子：
5
通讯作者：
Shimizu, S
中科院分区：
文献类型：
--
作者：
Sakuradani, E;Abe, T;Shimizu, S
一种丝状真菌，高山被孢霉1 S-4，在低于20 ℃的培养温度下不仅能产生花生四烯酸（AA; 20：4 n-6），而且能产生二十碳五烯酸（EPA; 20：5 n-3）。在这里，我们描述了一个基因（maw 3），编码一种新的ω 3-去饱和酶从M的分离和表征。alpina 1S-4.根据M. alpina 1 S-4 Delta 12-去饱和酶和Saccharomyces kluyveri omega 3-去饱和酶，来自M. alpina 1 S-4的克隆。蛋白质数据库同源性分析表明，其氨基酸序列与M. alpina 1 S-4 Δ 12-去饱和酶，而与Sac的同源性为36%。Kluyveri ω 3-去饱和酶。通过在酵母Sac中的表达，证实克隆的cDNA编码ω 3-去饱和酶。酿酒。酵母菌的脂肪酸组成分析表明，18-碳和20-碳n-3多不饱和脂肪酸（PUFA）的积累，通过转化外源18-碳和20-碳n-6 PUFA。M. alpina 1 S-4 omega 3-去饱和酶与来自Sac的已知真菌omega 3-去饱和酶不同。kluyveri和Saprolegnia diclina。植物，蓝藻和囊。kluyveri omega 3-去饱和酶使18-碳n-6 PUFA去饱和，Spr. diclina ω 3-去饱和酶使20-碳n-6 PUFA去饱和，秀丽隐杆线虫ω 3-去饱和酶优选18-碳n-6 PUFA而不是20-碳n-6 PUFA作为底物。M. alpina 1 S-4 omega 3-去饱和酶与C. elegans omega 3-去饱和酶，而M.当在酵母中表达时，alpina ω 3-去饱和酶可以更有效地将AA转化为EPA。分枝alpina 1 S-4 ω 3-去饱和酶是第一个已知的使用18-碳和20-碳n-6PUFA作为底物的真菌去饱和酶。
A filamentous fungus, Mortierella alpina 1S-4, is capable of producing not only arachidonic acid ( AA; 20: 4n-6) but also eicosapentaenoic acid (EPA; 20: 5n-3) below a cultural temperature of 20 degreesC. Here, we describe the isolation and characterization of a gene (maw3) that encodes a novel omega3-desaturase from M. alpina 1S-4. Based on the conserved sequence information for M. alpina 1S-4 Delta12-desaturase and Saccharomyces kluyveri omega3-desaturase, the omega3-desaturase gene from M. alpina 1S-4 was cloned. Homology analysis of protein databases revealed that the amino acid sequence showed 51% identity, at the highest, with M. alpina 1S-4 Delta12-desaturase, whereas it exhibited 36% identity with Sac. kluyveri omega3-desaturase. The cloned cDNA was confirmed to encode the omega3-desaturase by its expression in the yeast Sac. cerevisiae. Analysis of the fatty acid composition of the yeast transformant demonstrated that 18-carbon and 20-carbon n-3 polyunsaturated fatty acids (PUFAs) were accumulated through conversion of exogenous 18-carbon and 20-carbon n-6 PUFAs. The substrate specificity of the M. alpina 1S-4 omega3-desaturase differs from those of the known fungal omega3-desaturases from Sac. kluyveri and Saprolegnia diclina. Plant, cyanobacterial and Sac. kluyveri omega3-desaturases desaturate 18-carbon n-6 PUFAs, Spr. diclina omega3-desaturase desaturates 20-carbon n-6 PUFAs and Caenorhabditis elegans omega3-desaturase prefers 18-carbon n-6 PUFAs as substrates rather than 20-carbon n-6 PUFAs. The substrate specificity of M. alpina 1S-4 omega3-desaturase is rather similar to that of C. elegans omega3-desaturase, but the M. alpina omega3-desaturase can more effectively convert AA into EPA when expressed in yeast. The M. alpina 1S-4 omega3-desaturase is the first known fungal desaturase that uses both 18-carbon and 20-carbon n-6 PUFAs as substrates.