Catalyzes the 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. Required for growth on ethanol or acetate, but dispensable when fermentable carbon sources are available. Acts also on 2-methylisocitrate (By similarity). Plays an important role in plant pathogenicity. D-threo-isocitrate = glyoxylate + succinate (2S,3R)-3-hydroxybutane-1,2,3-tricarboxylate = pyruvate + succinate Carbohydrate metabolism; glyoxylate cycle; (S)-malate from isocitrate: step 1/2. Homotetramer. Expression is induced by starvation and acetate. Leads to limited hyphal growth in plants and extremely low germination rate of pycnidiospores. Belongs to the isocitrate lyase/PEP mutase superfamily. Isocitrate lyase family.