GCA_000012465.1 PMN2A_1621 definition 3-isopropylmalate dehydratase, small subunit GCA_000012465.1 PMN2A_1622 definition isopropylmalate isomerase large subunit GCA_000012465.1 PMN2A_0194 definition 3-isopropylmalate dehydrogenase GCA_000012465.1 PMN2A_0686 definition 2-isopropylmalate synthase