title: Characterization of Bacillus thuringiensis L-isoleucine dioxygenase for production of useful amino acids.
abstract: We determined the enzymatic characteristics of an industrially important biocatalyst, α-ketoglutarate-dependent l-isoleucine dioxygenase (IDO), which was found to be the enzyme responsible for the generation of (2S,3R,4S)-4-hydroxyisoleucine in Bacillus thuringiensis 2e2. Depending on the amino acid used as the substrate, IDO catalyzed three different types of oxidation reactions: hydroxylation, dehydrogenation, and sulfoxidation. IDO stereoselectively hydroxylated several hydrophobic aliphatic l-amino acids, as well as l-isoleucine, and produced (S)-3-hydroxy-l-allo-isoleucine, 4-hydroxy-l-leucine, (S)-4-hydroxy-l-norvaline, 4-hydroxy-l-norleucine, and 5-hydroxy-l-norleucine. The IDO reaction product of l-isoleucine, (2S,3R,4S)-4-hydroxyisoleucine, was again reacted with IDO and dehydrogenated into (2S,3R)-2-amino-3-methyl-4-ketopentanoate, which is also a metabolite found in B. thuringiensis 2e2. Interestingly, IDO catalyzed the sulfoxidation of some sulfur-containing l-amino acids and generated l-methionine sulfoxide and l-ethionine sulfoxide. Consequently, the effective production of various modified amino acids would be possible using IDO as the biocatalyst.
authors.affiliation: Industrial Microbiology, Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hibi
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawashima
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kodera
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Smirnov
authors.forename: Pavel M
authors.initials: PM
authors.lastname: Sokolov
authors.forename: Masakazu
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Sakayu
authors.initials: S
authors.lastname: Shimizu
authors.forename: Kenzo
authors.initials: K
authors.lastname: Yokozeki
authors.forename: Jun
authors.initials: J
authors.lastname: Ogawa
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D001413:Bacillus thuringiensis / Q000201:enzymology* / Q000378:metabolism*; D049308:Dioxygenases / Q000378:metabolism*; D006900:Hydroxylation; D007656:Ketoglutaric Acids / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D007656:Ketoglutaric Acids; D049308:Dioxygenases