homoaconitate hydratase
Homoaconitate hydratase homodimer, Methanocaldococcus jannaschii
Identifiers
EC no.	4.2.1.36
CAS no.	9030-68-6
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

The enzyme homoaconitate hydratase (EC 4.2.1.36) catalyzes the chemical reaction

(1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate ${\displaystyle \rightleftharpoons }$ (Z)-but-1-ene-1,2,4-tricarboxylate + H₂O

This enzyme belongs to the family of lyases, specifically the hydro-lyases, which cleave carbon-oxygen bonds. The systematic name of this enzyme class is (1R,2S)-1-hydroxybutane-1,2,4-tricarboxylate hydro-lyase [(Z)-but-1-ene-1,2,4-tricarboxylate-forming]. Other names in common use include homoaconitase, cis-homoaconitase, HACN, Lys4, LysF, and 2-hydroxybutane-1,2,4-tricarboxylate hydro-lyase (incorrect). This enzyme participates in lysine biosynthesis.

• Strassman M, Ceci LN (1966). "Enzymatic formation of cis-homoaconitic acid, an intermediate in lysine biosynthesis in yeast". J. Biol. Chem. 241 (22): 5401–7. PMID 5954805.
• Jia Y, Tomita T, Yamauchi K, Nishiyama M, Palmer DR (2006). "Kinetics and product analysis of the reaction catalysed by recombinant homoaconitase from Thermus thermophilus". Biochem. J. 396 (3): 479–85. doi:10.1042/BJ20051711. PMC 1482822. PMID 16524361.
• Zabriskie TM, Jackson MD (2000). "Lysine biosynthesis and metabolism in fungi". Nat. Prod. Rep. 17 (1): 85–97. doi:10.1039/a801345d. PMID 10714900.