Control Mechanism for Carbon‐Chain Length in Polyunsaturated Fatty‐Acid Synthases
作者:Shohei Hayashi、Mai Naka、Kenshin Ikeuchi、Makoto Ohtsuka、Kota Kobayashi、Yasuharu Satoh、Yasushi Ogasawara、Chitose Maruyama、Yoshimitsu Hamano、Tetsuro Ujihara、Tohru Dairi
DOI:10.1002/anie.201900771
日期:2019.5.13
Polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are essential fatty acids. PUFA synthases are composed of three to four subunits and each create a specific PUFA without undesirable byproducts. However, detailed biosynthetic mechanisms for controlling final product profiles have been obscure. Here, the bacterial DHA and EPA synthases were carefully
多不饱和脂肪酸(PUFA),如二十二碳六烯酸(DHA)和二十碳五烯酸(EPA)是必需脂肪酸。PUFA合成酶由3至4个亚基组成,每一个均产生特定的PUFA,而没有不希望的副产物。但是,用于控制最终产品特征的详细生物合成机制一直不清楚。在此,通过体内和体外实验仔细剖析了细菌DHA和EPA合成酶。用两个KS结构域(KS A和KS C)和酰基-酰基载体蛋白(ACP)底物进行的体外分析显示,KS A接受短链至中链的底物,而KS C接受中链至长链的底物。出乎意料的是,从C 18到C的冷凝图20是EPA生物合成中的最后一个延伸步骤,是由EPA和DHA合酶中的KS A结构域催化的。相反,DHA合酶中的KS C结构域催化了DHA生物合成的最后一个延伸步骤C 20至C 22的缩合。因此,KS C域决定了链的长度。