homoisocitrate dehydrogenase
Homoisocitrate dehydrogenase tetramer, Thermus thermophilus
Identifiers
EC no.	1.1.1.87
CAS no.	37250-23-0
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a homoisocitrate dehydrogenase (EC 1.1.1.87) is an enzyme that catalyzes the chemical reaction

(1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate + NAD⁺ ${\displaystyle \rightleftharpoons }$ 2-oxoadipate + CO₂ + NADH + H⁺

Thus, the two substrates of this enzyme are (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate and NAD⁺, whereas its 4 products are 2-oxoadipate, CO₂, NADH, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate:NAD⁺ oxidoreductase (decarboxylating). Other names in common use include 2-hydroxy-3-carboxyadipate dehydrogenase, 3-carboxy-2-hydroxyadipate dehydrogenase, homoisocitric dehydrogenase, (−)-1-hydroxy-1,2,4-butanetricarboxylate:NAD⁺ oxidoreductase, (decarboxylating), 3-carboxy-2-hydroxyadipate:NAD⁺ oxidoreductase (decarboxylating), and HICDH. This enzyme participates in lysine biosynthesis.

As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code 1X0L.

• Strassman M, Ceci LN (1965). "Enzymatic formation of alpha-ketoadipic acid from homoisocitric acid". J. Biol. Chem. 240 (11): 4357–61. doi:10.1016/S0021-9258(18)97069-9. PMID 4284830.
• Rowley B, Tucci AF (1970). "Homoisocitric dehydrogenase from yeast". Arch. Biochem. Biophys. 141 (2): 499–510. doi:10.1016/0003-9861(70)90167-0. PMID 4395693.
• Zabriskie TM, Jackson MD (2000). "Lysine biosynthesis and metabolism in fungi". Nat. Prod. Rep. 17 (1): 85–97. doi:10.1039/a801345d. PMID 10714900.