Wei D Sh, Li M Ch, Zhang X X, Zhou H, Xing L J
Tianjin Key Laboratory of Microbial Functional Genomics, Department of Microbiology, Nankai University, Tianjin 300071, PR China.
Acta Biochim Pol. 2006;53(4):753-9. Epub 2006 Oct 26.
The methylotrophic yeast Pichia pastoris GS115, a widely used strain in production of various heterologous proteins, especially membrane-bound enzymes, can also produce linoleic and linolenic acids, which indicates the existence of membrane-bound Delta12 and Delta15-fatty acid desaturases. This paper describes the cloning and functional characterization of a novel Delta12-fatty acid desaturase gene from this methylotrophic yeast. The open reading frame of the gene (named Pp-FAD12) is 1263 bp in size and encodes a 420-amino-acid peptide. The deduced Pp-FAD12 protein shows high identity (50-67%) with Delta12-fatty acid desaturases from other fungi. It also shows a high identity (57%) with Delta15-fatty acid desaturase (named Sk-FAD15) from Saccharomyces kluyveri. Expression of Pp-FAD12 in polyunsaturated fatty acids non-producing yeast Saccharomyces cerevisiae demonstrated that its product converted oleic acid (18 : 1) to linoleic acid (18 : 2). This result suggests that Pp-FAD12 encodes a novel Delta12-fatty acid desaturase in P. pastoris GS115. This is the first report about the cloning and functional characterization of Delta12-fatty acid desaturase gene in methylotrophic yeast.
甲醇营养型酵母毕赤酵母GS115是生产各种异源蛋白，尤其是膜结合酶时广泛使用的菌株，它也能产生亚油酸和亚麻酸，这表明存在膜结合的Δ12和Δ15脂肪酸去饱和酶。本文描述了从这种甲醇营养型酵母中克隆并鉴定一种新型Δ12脂肪酸去饱和酶基因的功能。该基因（命名为Pp-FAD12）的开放阅读框大小为1263 bp，编码一个420个氨基酸的肽段。推导的Pp-FAD12蛋白与其他真菌的Δ12脂肪酸去饱和酶具有高度同源性（50 - 67%）。它与克鲁维酵母的Δ15脂肪酸去饱和酶（命名为Sk-FAD15）也具有高度同源性（57%）。Pp-FAD12在不产生多不饱和脂肪酸的酿酒酵母中的表达表明，其产物将油酸（18 : 1）转化为亚油酸（18 : 2）。这一结果表明Pp-FAD12在毕赤酵母GS115中编码一种新型的Δ12脂肪酸去饱和酶。这是关于甲醇营养型酵母中Δ12脂肪酸去饱和酶基因克隆和功能鉴定的首次报道。
