Isopropylmalate dehydrogenase

Isopropylmalate dehydrogenase (IMDH) catalyzes the oxidative decarboxylation of 3-isopropylmalate (3IPM) to 2-oxo-4-methylvalerate. This reaction is a step in the biosynthesis of leucine in bacteria and fungi. IMDH uses NAD as a cofactor. IMDH is a bifunctional enzyme that catalyzes dehydrogenation and decarboxylation in the presence of NAD and a divalent cation.

3D structures of isopropylmalate dehydrogenase3D structures of isopropylmalate dehydrogenase

3-isopropylmalate dehydrogenase

1ipd, 1xaa, 1xab, 1xac, 1xad, 1osi, 1dpz, 1dr0, 1dr8, 2y3z – TtIMDH – Thermus thermophilus
1idm, 1osj, 1wal, 1gc8, 1gc9, 1g2u – TtIMDH (mutant)
2ayq, 1v53 – BcIMDH – Bacillus coagulans
1v5b – BcIMDH (mutant)
1cm7 – IMDH – Escherichia coli
1vlc – IMDH – Thermotoga maritima
1v7l - IMDH – Pyrococcus horikoshii
1w0d, 2g4o - MtIMDH - Mycobacterium tuberculosis
3h5e, 3h5h, 3h5j - MtIMDH small subunit
2hcu – IMDH small subunit – Streptococcus mutans
3q3w - IMDH small subunit – Campylobacter jejuni
3rsw - IMDH – Arabidopsis thaliana
3uih - IMDH – Bacillus

IMDH binary complexes

1hex – TtIMDH + NAD
2y40 - TtIMDH + Mn
1cnz – IMDH + Mn – Salmonella typhimurium
1wpw - IMDH + Mg – Sulfolobus tokodaii
2pkp - IMDH small subunit + Zn – Methanocaldococcus jannaschii

IMDH ternary complexes

2y42 - TtIMDH + Mg + NAD
2ztw - TtIMDH + Mg + inhibitor + NAD
2y41 - TtIMDH + 3IPM + Mn
1a05 – IMDH + 3IPM + Mg - Acidithiobacillus ferrooxidans
3vkz, 3vl2, 3vl3, 3vl4, 3vl6, 3vl7 - SoIMDH + 3IPM + Ca – Shewanella oneidensis
3vmj - SoIMDH + 3IPM + Mg
3vmk - IMDH + 3IPM + Mg – Shewanella bethica

2-isopropylmalate dehydrogenase

3fig - MtIMDH (mutant) + Zn