United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo, Japan.
FEBS Lett. 2011 Jun 23;585(12):1879-83. doi: 10.1016/j.febslet.2011.04.057. Epub 2011 Apr 30.
The moss Physcomitrella patens produces both ent-kaurene and ent-kaurenoic acid, which are intermediates of gibberellin biosynthesis in flowering plants. The CYP701 superfamily of cytochrome P450s functions as ent-kaurene oxidases in the biosynthesis of ent-kaurenoic acid. A candidate gene encoding ent-kaurene oxidase in P. patens, CYP701B1, was cloned and heterologously expressed in yeast to examine enzyme activities in vitro. The recombinant CYP701B1 protein catalyzed the oxidation reaction from ent-kaurene to ent-kaurenoic acid. CYP701B1 activity was highly resistant to the ent-kaurene oxidase inhibitor uniconazole-P (IC(50) 64 μM), even though the activity of Arabidopsis ent-kaurene oxidase (CYP701A3) was sensitive (IC(50) 0.26 μM).
苔藓植物小立碗藓既能产生贝壳杉烯也能产生贝壳杉烯酸，而这两者都是开花植物中赤霉素生物合成的中间产物。细胞色素 P450 的 CYP701 超家族在贝壳杉烯酸的生物合成中充当贝壳杉烯氧化酶。我们从小立碗藓中克隆了一个编码贝壳杉烯氧化酶的候选基因 CYP701B1，并在酵母中异源表达以研究体外的酶活性。重组 CYP701B1 蛋白能催化贝壳杉烯到贝壳杉烯酸的氧化反应。CYP701B1 活性对贝壳杉烯氧化酶抑制剂 uni-conazole-P（IC50=64 μM）具有很强的抗性，而拟南芥贝壳杉烯氧化酶（CYP701A3）对此抑制剂很敏感（IC50=0.26 μM）。
