l-Isovaline biosynthesis by TqaLFM-ti from Tolypocladium inflatum was demonstrated in vitro. The biochemical analysis of the α-ketoglutarate-dependent oxygenase TqaL-ti revealed that it produces (2S,3S)-3-ethyl-3-methylaziridine-2-carboxylic acid from l-isoleucine, thus exhibiting a stereoselectivity different from those of the reported homologues. Remarkably, a single mutation on I295 in TqaL-ti completely exchanged its stereoselectivity to produce the C-3 stereoisomer. TqaFM-ti generates d-isovaline from (2S,3R)-aziridine-2-carboxylic acid, suggesting that the stereochemistry of the TqaL product defines that of isovaline.

中文翻译：

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L-异缬氨酸生物合成中氮丙啶形成 α-酮戊二酸依赖性加氧酶的表征


体外证明了Tolypocladium inflatum中 TqaLFM -ti的l-异缬氨酸生物合成。对α-酮戊二酸依赖性加氧酶TqaL -ti的生化分析表明，它从l-异亮氨酸产生( 2S , 3S )-3-乙基-3-甲基氮丙啶-2-羧酸，从而表现出与那些不同的立体选择性。所报道的同系物。值得注意的是，TqaL- ti中 I295 的单个突变完全改变了其立体选择性，产生了 C-3 立体异构体。 TqaFM- ti从 (2 S ,3 R )-氮丙啶-2-羧酸生成d -异缬氨酸，这表明 TqaL 产物的立体化学定义了异缬氨酸的立体化学。