IUBMB Enzyme Nomenclature


Accepted name: homocitrate synthase

Reaction: acetyl-CoA + H2O + 2-oxoglutarate = (R)-2-hydroxybutane-1,2,4-tricarboxylate + CoA

For diagram click here, another example.

Glossary: (R)-homocitrate = (R)-2-hydroxybutane-1,2,4-tricarboxylate

Other name(s): 2-hydroxybutane-1,2,4-tricarboxylate 2-oxoglutarate-lyase (CoA-acetylating); acetyl-coenzyme A:2-ketoglutarate C-acetyl transferase; homocitrate synthetase; HCS

Systematic name: acetyl-CoA:2-oxoglutarate C-acetyltransferase (thioester-hydrolysing, carboxymethyl forming)

Comments: Belongs in the α-aminoadipate pathway of lysine synthesis, along with EC, homoaconitate hydratase. The enzyme also acts with oxaloacetate as substrate, but more slowly [2,3].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9075-60-9


1. Strassman, M. and Ceci, L.N. Enzymatic formation of homocitric acid, an intermediate in lysine biosynthesis. Biochem. Biophys. Res. Commun. 14 (1964) 262-267. [PMID: 5836514]

2. Wulandari, A.P., Miyazaki, J., Kobashi, N., Nishiyama, M., Hoshino, T. and Yamane, H. Characterization of bacterial homocitrate synthase involved in lysine biosynthesis. FEBS Lett. 522 (2002) 35-40. [PMID: 12095615]

3. Andi, B., West, A.H. and Cook, P.F. Kinetic mechanism of histidine-tagged homocitrate synthase from Saccharomyces cerevisiae. Biochemistry 43 (2004) 11790-11795. [PMID: 15362863]

[EC created 1972 as EC, transferred 2002 to EC]

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