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Updated: Jul 5, 2025

Synthesis of 1,2-Azaborines and the Preparation of Their Protein Complexes with T4 Lysozyme Mutants
Published on: March 25, 2017
Characterization of Aziridine-Forming α-Ketoglutarate-Dependent Oxygenase in l-Isovaline Biosynthesis
Lu Zhou1,2, Takayoshi Awakawa1,2, Richiro Ushimaru1,3
1Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan.
Abstract:
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.
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