Sequence variation determining stereochemistry of a Δ11 desaturase active in moth sex pheromone biosynthesis
Sequence variation determining stereochemistry of a Δ11 desaturase active in moth sex pheromone biosynthesis
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DOI：
10.1016/j.ibmb.2016.05.002
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发表时间：
2016-07-01
影响因子：
3.8
通讯作者：
Lofstedt, Christer
中科院分区：
文献类型：
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作者：
Ding, Bao-Jian;Carraher, Colm;Lofstedt, Christer
斜带卷叶蛾Choristoneura rosaceana的Delta 11脱饱和酶能产生饱和的肉豆蔻酸，生成(E)-11-十四烯酸和(Z)-11-十四烯酸的混合物，Z异构体过量(35：65)。斑点火蛾Choristoneura parallela的去饱和酶也作用于肉豆蔻酸底物，但产生几乎纯的(E)-11-十四烯酸。两种去饱和酶的氨基酸同源性为92%，氨基酸相似性为97%。这两种去饱和酶有24种不同的氨基酸。我们在所有这些位置构建了突变，以确定决定产品立体化学的位置。我们用酵母功能实验证明了蛋白(258E)胞质羧基末端的一个氨基酸对酒渣鼻去饱和酶的Z活性是关键的。将谷氨酸(E)突变为天冬氨酸(D)可将酒渣草的酶转化为具有类似C-Parallela活性的去饱和酶，而该酶的相互突变可将其转化为一种酶，从而产生中间的：36 E/Z产物比。我们讨论了这种氨基酸变化和去饱和酶的立体化学性质之间的因果联系，以及去饱和酶突变在信息素进化中的作用。(C)2016年提交人。爱思唯尔有限公司出版。
A Delta 11 desaturase from the oblique banded leaf roller moth Choristoneura rosaceana takes the saturated myristic acid and produces a mixture of (E)-11-tetradecenoate and (Z)-11-tetradecenoate with an excess of the Z isomer (35:65). A desaturase from the spotted fireworm moth Choristoneura parallela also operates on myristic acid substrate but produces almost pure (E)-11-tetradecenoate. The two desaturases share 92% amino acid identity and 97% amino acid similarity. There are 24 amino acids differing between these two desaturases. We constructed mutations at all of these positions to pinpoint the sites that determine the product stereochemistry. We demonstrated with a yeast functional assay that one amino acid at the cytosolic carboxyl terminus of the protein (258E) is critical for the Z activity of the C. rosaceana desaturase. Mutating the glutamic acid (E) into aspartic acid (D) transforms the C. rosaceana enzyme into a desaturase with C parallela-like activity, whereas the reciprocal mutation of the C. parallela desaturase transformed it into an enzyme producing an intermediate 64:36 E/Z product ratio. We discuss the causal link between this amino acid change and the stereochemical properties of the desaturase and the role of desaturase mutations in pheromone evolution. (C) 2016 The Authors. Published by Elsevier Ltd.