Off-Loading Mechanism of Products in Polyunsaturated Fatty Acid Synthases
Off-Loading Mechanism of Products in Polyunsaturated Fatty Acid Synthases
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DOI：
10.1021/acschembio.0c00075
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发表时间：
2020-03-20
影响因子：
4
通讯作者：
Dairi, Tohru
中科院分区：
文献类型：
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作者：
Hayashi, Shohei;Ogasawara, Yasushi;Dairi, Tohru
海洋微生物通过由三个或四个多肽组成的多不饱和脂肪酸（PUFA）酶以类似于脂肪酸脱氢酶（FAS）的方式从头生物合成多不饱和脂肪酸，如二十二碳六烯酸和二十碳五烯酸。FAS通常具有硫酯酶（TE）结构域，以从酰基载体蛋白（ACP）-束缚的中间体释放游离脂肪酸。在这里，我们通过体内和体外实验研究了微藻和细菌PUFA降解酶的卸载机制。在体外实验与酰基转移酶（AT）样结构域和酰基ACP底物清楚地表明，AT样结构域催化水解酰基ACP产生游离脂肪酸。
Marine microorganisms de novo biosynthesize polyunsaturated fatty acids such as docosahexaenoic acid and eicosapentaenoic acid by polyunsaturated fatty acid (PUFA) synthases composed of three or four polypeptides in a manner similar to fatty acid synthases (FASs). FASs usually possess thioesterase (TE) domains to release free fatty acids from acyl carrier protein (ACP)-tethered intermediates. Here, we investigated the off-loading mechanism with microalgal and bacterial PUFA synthases through in vivo and in vitro experiments. The in vitro experiments with acyltransferase (AT)-like domains and acyl-ACP substrates clearly demonstrated that the AT-like domains catalyzed the hydrolysis of acyl-ACPs to yield free fatty acids.