Steroids are the most widely marketed products by the pharmaceutical industry after antibiotics. Steroid hydroxylation is one of the most important functionalizations because their derivatives enable a higher biological activity compared to their less polar non-hydroxylated analogs. Bacterial cytochrome P450s constitute promising biocatalysts for steroid hydroxylation due to their high expression level in common workhorses like Escherichia coli. However, they often suffer from wrong or insufficient regio- and/or stereoselectivity, low activity, narrow substrate range as well as insufficient thermostability, which hampers their industrial application. Fortunately, these problems can be generally solved by protein engineering based on directed evolution and rational design. In this work, an overview of recent developments on the engineering of bacterial cytochrome P450s for steroid hydroxylation is presented.

中文翻译：

---

通过定向进化和合理设计实现细菌细胞色素P450催化的区域和立体选择性甾体羟基化

类固醇是仅次于抗生素的制药业最广泛销售的产品。甾体羟基化是最重要的官能化之一，因为与它们的极性较小的非羟基化类似物相比，其衍生物具有更高的生物活性。细菌细胞色素P450构成有希望的类固醇羟基化生物催化剂，因为它们在诸如大肠杆菌等常见工作液中具有高表达水平。。然而，它们经常遭受错误或不充分的区域和/或立体选择性，低活性，窄的底物范围以及不足的热稳定性，这阻碍了它们的工业应用。幸运的是，这些问题通常可以通过基于定向进化和合理设计的蛋白质工程来解决。在这项工作中，概述了用于甾体羟基化的细菌细胞色素P450工程改造的最新进展。