Functional expression of genes involved in the biosynthesis of the novel polyketide chain extension unit, methoxymalonyl-acyl carrier protein, and engineered biosynthesis of 2-desmethyl-2-methoxy-6-deoxyerythronolide B
Functional expression of genes involved in the biosynthesis of the novel polyketide chain extension unit, methoxymalonyl-acyl carrier protein, and engineered biosynthesis of 2-desmethyl-2-methoxy-6-deoxyerythronolide B
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DOI：
10.1021/ja0127483
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发表时间：
2002-05-15
影响因子：
15
通讯作者：
Floss, HG
中科院分区：
文献类型：
--
作者：
Kato, Y;Bai, LQ;Floss, HG
在变铅青链霉菌中共表达了来自Actinosynnema pretiosum的安丝菌素生物合成基因簇的5个基因亚簇asm13 − 17，以及来自多孢红链霉菌的编码6-脱氧丙二酸B（6-DE B）合酶的基因，其中甲基丙二酸特异性AT 6结构域已被来自吸水链霉菌FK 520簇的甲氧基丙二酸特异性AT 8结构域所取代。工程菌株产生了预测的产物2-去甲基-2-甲氧基-DEB，而不是6-DEB和2-去甲基-6-DEB，后者是在缺乏asm13 − 17盒的情况下形成的，表明asm13 − 17足以合成这种不寻常的链延伸单元。从盒中删除编码甲基转移酶的asm17，得到6-DEB而不是其羟基类似物，表明其掺入需要延伸单元的甲基化。
A subcluster of five genes,asm13−17, from the ansamitocin biosynthetic gene cluster ofActinosynnema pretiosumwas coexpressed inStreptomyces lividanswith the genes encoding the 6-deoxyerythronolide B (6-DEB) synthase fromSaccharopolysporaerythraea, in which the methylmalonate-specifying AT6 domain had been replaced by the methoxymalonate-specifying AT8 domain from the FK520 cluster ofStreptomyces hygroscopicus. The engineered strain produced the predicted product, 2-desmethyl-2-methoxy-DEB, instead of 6-DEB and 2-desmethyl-6-DEB, which were formed in the absence of theasm13−17cassette, indicating thatasm13−17are sufficient for synthesis of this unusual chain extension unit. Deletion ofasm17, encoding a methyltransferase, from the cassette gave 6-DEB instead of its hydroxy analogue, indicating that methylation of the extender unit is required for its incorporation.