Performs an essential role in the oxidative function of the citric acid cycle. Heterooligomer of catalytic and regulatory subunits. Interacts with 14-3-3-like proteins GRF1 GRF3 and GRF8 (PubMed:22104211). Mainly expressed at a low level in pollen. Belongs to the isocitrate and isopropylmalate dehydrogenases family.