Glawischnig E, Grün S, Frey M, Gierl A
Institut für Genetik, Technische Universität München, Garching, Germany.
Phytochemistry. 1999 Mar;50(6):925-30. doi: 10.1016/s0031-9422(98)00318-5.
DIBOA and DIMBOA are secondary metabolites of grasses which function as natural pesticides. The four maize genes BX2 through BX5 encode cytochrome P450-dependent monooxygenases that catalyse four consecutive reactions in the biosynthesis of these secondary products. Although BX2-BX5 share significant sequence homology, the four enzymes have evolved into specific enzymes each catalysing predominantly only one reaction in the pathway. In addition to these natural reactions, BX3 hydroxylates 1,4-benzoxazin-3-one and BX2 shows pCMA demethylase activity. With respect to DIBOA biosynthesis, identical enzymatic reactions have been found in rye as compared to maize, indicating early evolution of the P450 enzymes in the grasses.
DIBOA和DIMBOA是禾本科植物的次生代谢产物，起到天然杀虫剂的作用。玉米的四个基因BX2至BX5编码细胞色素P450依赖性单加氧酶，它们在这些次生产物的生物合成中催化四个连续反应。尽管BX2 - BX5具有显著的序列同源性，但这四种酶已进化为特定的酶，每种酶主要仅催化该途径中的一个反应。除了这些天然反应外，BX3使1,4 - 苯并恶嗪 - 3 - 酮羟基化，BX2具有对氯甲基苯甲醚脱甲基酶活性。关于DIBOA的生物合成，与玉米相比，在黑麦中发现了相同的酶促反应，这表明禾本科植物中P450酶的早期进化。
