Reaction: ATP + 2-oxoglutarate + HCO3- = ADP + phosphate + oxalosuccinate
For diagram click here.
Glossary: oxalosuccinate = 1-oxopropane-1,2,3-tricarboxylate
Other name(s): oxalosuccinate synthetase; carboxylating factor for ICDH (incorrect); CFI; OGC
Comments: A biotin-containing enzyme that requires Mg2+ for activity. It was originally thought  that this enzyme was a promoting factor for the carboxylation of 2-oxoglutarate by EC 126.96.36.199, isocitrate dehydrogenase (NAD+), but this has since been disproved . The product of the reaction is unstable and is quickly converted into isocitrate by the action of EC 188.8.131.52 .
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 60382-75-4
1. Aoshima, M., Ishii, M. and Igarashi, Y. A novel biotin protein required for reductive carboxylation of 2-oxoglutarate by isocitrate dehydrogenase in Hydrogenobacter thermophilus TK-6. Mol. Microbiol. 51 (2004) 791-798. [PMID: 14731279]
2. Aoshima, M. and Igarashi, Y. A novel oxalosuccinate-forming enzyme involved in the reductive carboxylation of 2-oxoglutarate in Hydrogenobacter thermophilus TK-6. Mol. Microbiol. 62 (2006) 748-759. [PMID: 17076668]