Molecular cloning of N-methylputrescine oxidase from tobacco
Molecular cloning of N-methylputrescine oxidase from tobacco
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DOI：
10.1093/pcp/pcm018
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发表时间：
2007-03-01
影响因子：
4.9
通讯作者：
Hashimoto, Takashi
中科院分区：
文献类型：
--
作者：
Katoh, Akira;Shoji, Tsubasa;Hashimoto, Takashi
烟草属物种中的尼古丁生物合成需要N-甲基腐胺的氧化脱氨基，由N-甲基腐胺氧化酶（MPO）催化。在烟草基因的筛选中，烟草突变体中的尼古丁生物合成调节改变下调，我们确定了两个同源MPO cDNA编码的一个特定的亚类的二胺氧化酶。烟草MPO基因在根中特异性表达，茉莉酸处理对其表达有明显的调控作用。在大肠杆菌中表达的重组MPO蛋白形成同源二聚体和脱氨基N-甲基腐胺比对称二胺更有效。这些结果表明MPO是从一般的二胺氧化酶进化而来的，在尼古丁生物合成中起着有效的作用。
Nicotine biosynthesis in Nicotiana species requires an oxidative deamination of N-methylputrescine, catalyzed by N-methylputrescine oxidase (MPO). In a screen for tobacco genes that were down-regulated in a tobacco mutant with altered regulation of nicotine biosynthesis, we identified two homologous MPO cDNAs which encode diamine oxidases of a particular subclass. Tobacco MPO genes were expressed specifically in the root, and tip-regulated by jasmonate treatment. Recombinant MPO protein expressed in Escherichia coli formed a homodimer and deaminated N-methylputrescine more efficiently than symmetrical diamines. These results indicate that MPO evolved from general diamine oxidases to function effectively in nicotine biosynthesis.