1.1.1.86 ketol-acid reductoisomerase (NADP+) L-isoleucine biosynthesis I (from threonine) - 2.2.1.6 acetolactate synthase L-isoleucine biosynthesis I (from threonine) - 2.6.1.42 branched-chain-amino-acid transaminase L-isoleucine biosynthesis I (from threonine) - 3.5.99.10 2-iminobutanoate/2-iminopropanoate deaminase L-isoleucine biosynthesis I (from threonine) - 4.2.1.9 dihydroxy-acid dehydratase L-isoleucine biosynthesis I (from threonine) -