StyA1 and StyA2B from Rhodococcus opacus 1CP: a Multifunctional Styrene Monooxygenase System
StyA1 and StyA2B from Rhodococcus opacus 1CP: a Multifunctional Styrene Monooxygenase System
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DOI：
10.1128/jb.00723-10
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发表时间：
2010-10-01
影响因子：
3.2
通讯作者：
Schloemann, Michael
中科院分区：
文献类型：
--
作者：
Tischler, Dirk;Kermer, Rene;Schloemann, Michael
双组分黄素蛋白单加氧酶是新兴的生物催化剂，通常由一个单加氧酶和一个还原酶组分组成。在此我们表明，不透明红球菌1CP编码一个多功能对映选择性黄素蛋白单加氧酶系统，该系统由一个单一的苯乙烯单加氧酶（SMO）（StyA1）和另一个与NADH - 黄素氧化还原酶融合的苯乙烯单加氧酶（StyA2B）组成。StyA1和StyA2B以StyA2B提供的FADH(2)为代价，将苯乙烯和化学类似物转化为相应的环氧化物。StyA1/StyA2B系统在StyA1和StyA2B等摩尔比时呈现出最高的单加氧酶活性，这表明（瞬时）蛋白质复合物的形成。当由假单胞菌属VLB120的StyB或不透明红球菌1CP的PheA2提供FADH(2)时，StyA1也具有活性。然而，在这两种情况下，还原酶都会产生过量的FADH(2)，导致NADH的大量浪费。StyA1的环氧化速率在很大程度上取决于还原酶的类型。这支持了FADH(2)诱导的StyA1激活需要蛋白质间的相互作用。我们得出结论，StyA1/StyA2B系统代表了一种新型的多功能黄素蛋白单加氧酶。其独特的辅因子利用机制为生物技术应用提供了新的机遇，并且从结构和进化的角度来看具有高度相关性。
Two-component flavoprotein monooxygenases are emerging biocatalysts that generally consist of a monooxygenase and a reductase component. Here we show that Rhodococcus opacus 1CP encodes a multifunctional enantioselective flavoprotein monooxygenase system composed of a single styrene monooxygenase (SMO) (StyA1) and another styrene monooxygenase fused to an NADH-flavin oxidoreductase (StyA2B). StyA1 and StyA2B convert styrene and chemical analogues to the corresponding epoxides at the expense of FADH(2) provided from StyA2B. The StyA1/StyA2B system presents the highest monooxygenase activity in an equimolar ratio of StyA1 and StyA2B, indicating (transient) protein complex formation. StyA1 is also active when FADH(2) is supplied by StyB from Pseudomonas sp. VLB120 or PheA2 from Rhodococcus opacus 1CP. However, in both cases the reductase produces an excess of FADH(2), resulting in a high waste of NADH. The epoxidation rate of StyA1 heavily depends on the type of reductase. This supports that the FADH(2)-induced activation of StyA1 requires interprotein communication. We conclude that the StyA1/StyA2B system represents a novel type of multifunctional flavoprotein monooxygenase. Its unique mechanism of cofactor utilization provides new opportunities for biotechnological applications and is highly relevant from a structural and evolutionary point of view.