Sakamoto T, Wada H, Nishida I, Ohmori M, Murata N
Department of Molecular Biomechanics, Graduate University of Advanced Studies, Okazaki, Japan.
Plant Mol Biol. 1994 Feb;24(4):643-50. doi: 10.1007/BF00023560.
Cyanobacterial genes for enzymes that desaturate fatty acids at the delta 12 position, designated desA, were isolated from Synechocystis PCC6714, Synechococcus PCC7002 and Anabaena variabilis by cross-hybridization with a DNA probe derived from the desA gene of Synechocystis PCC6803. The genes of Synechocystis PCC6714, Synechococcus PCC7002 and A. variabilis encode proteins of 349, 347 and 350 amino acid residues, respectively. The transformation of Synechococcus PCC7942 with the desA genes from Synechocystis PCC6714, Synechococcus PCC7002 and A. variabilis was associated with the ability to introduce a second double bond at the delta 12 position of fatty acids. The amino acid sequence of the products of the desA genes revealed the presence of four conserved domains. Since one of the conserved domains was also found in the amino acid sequences of omega 3 desaturases of Brassica napus and mung bean, this domain may play an essential role in the introduction of a double bond into fatty acids bound to membrane lipids.
通过与源自集胞藻PCC6803的desA基因的DNA探针进行交叉杂交，从集胞藻PCC6714、聚球藻PCC7002和多变鱼腥藻中分离出编码在Δ12位使脂肪酸去饱和的酶的蓝细菌基因desA。集胞藻PCC6714、聚球藻PCC7002和多变鱼腥藻的基因分别编码含349、347和350个氨基酸残基的蛋白质。用来自集胞藻PCC6714、聚球藻PCC7002和多变鱼腥藻的desA基因转化聚球藻PCC7942，与在脂肪酸的Δ12位引入第二个双键的能力相关。desA基因产物的氨基酸序列显示存在四个保守结构域。由于在甘蓝型油菜和绿豆的ω3去饱和酶的氨基酸序列中也发现了其中一个保守结构域，该结构域可能在将双键引入与膜脂结合的脂肪酸中起重要作用。
