The sesterterpene synthase SmTS1 from Streptomyces mobaraensis contains several unusual residues in positions that are otherwise highly conserved. Site-directed mutagenesis experiments for these residues are reported that showed different effects, resulting in some cases in an improved catalytic activity, but in other cases in a loss of enzyme function. For other enzyme variants a functional switch was observed, turning SmTS1 from a sesterterpene into a diterpene synthase. This article gives rational explanations for these findings that may generally allow for protein engineering of other terpene synthases to improve their catalytic efficiency or to change their functions.

中文翻译：

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靶向萜烯合酶中的活性位点残基和结构锚定位置

来自Streptomyces mobaraensis的二萜合酶 SmTS1在高度保守的位置包含几个不寻常的残基。据报道，这些残基的定点诱变实验显示出不同的效果，导致在某些情况下催化活性提高，但在其他情况下酶功能丧失。对于其他酶变体，观察到功能转换，将 SmTS1 从二萜合成酶转变为二萜合酶。本文对这些发现给出了合理的解释，这些发现通常可能允许对其他萜烯合酶进行蛋白质工程，以提高其催化效率或改变其功能。