Involved in the metabolic adaptation in response to environmental changes. Catalyzes the reversible formation of succinate and glyoxylate from isocitrate, a key step of the glyoxylate cycle, which operates as an anaplerotic route for replenishing the tricarboxylic acid cycle during growth on fatty acid substrates. D-threo-isocitrate = glyoxylate + succinate Carbohydrate metabolism; glyoxylate cycle; (S)-malate from isocitrate: step 1/2. Homotetramer. Belongs to the isocitrate lyase/PEP mutase superfamily. Isocitrate lyase family.