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 Divalent metal cations. Mn(2+) or Co(2+) can be used. Inhibited by 3-phosphoglycerate, 6-phosphogluconate, phosphoenolpyruvate (PEP), fructose 1,6-bisphosphate, glycolate, oxalate, and itaconate. Optimum pH is 7.3. Optimum temperature is 40 degrees Celsius. Above 45 degrees Celsius, the enzyme is denaturated. Carbohydrate metabolism; glyoxylate cycle; (S)-malate from isocitrate: step 1/2. Homotetramer. Activated by RamA and repressed by RamB. Cells lacking this gene are unable to grow on acetate as carbon source. Belongs to the isocitrate lyase/PEP mutase superfamily. Isocitrate lyase family.