Reaction: 3-oxoisoapionate 4-phosphate + H2O = glycolate + 3-phospho-D-glycerate
Glossary: 3-oxoisoapionate = 2,4-dihydroxy-2-(hydroxymethyl)-3-oxobutanoate
Other name(s): oiaT (gene name)
Systematic name: 3-oxoisoapionate-4-phosphate transcarboxylase/glycolylhydrolase (3-phospho-D-glycerate-forming)
Comments: The enzyme, which belongs to the RuBisCO-like-protein (RLP) superfamily, has been characterized from several bacterial species. It participates in the degradation of D-apionate. The reaction is initiated by decarboxylation to generate a stabilized enediolate intermediate, with the sequestered CO2 carboxylating the adjacent enediolate carbon atom. The resulting 3-ketose-1-phosphate intermediate is hydrolysed, as in the authentic RuBisCO-catalysed reaction, to generate glycolate and 3-phospho-D-glycerate. Stereospecificity of 3-oxoisoapionate 4-phosphate has not been determined.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
1. Carter, M.S., Zhang, X., Huang, H., Bouvier, J.T., Francisco, B.S., Vetting, M.W., Al-Obaidi, N., Bonanno, J.B., Ghosh, A., Zallot, R.G., Andersen, H.M., Almo, S.C. and Gerlt, J.A. Functional assignment of multiple catabolic pathways for D-apiose. Nat. Chem. Biol. 14 (2018) 696-705. [PMID: 29867142]