Component of the methylcitrate cycle that catalyzes the synthesis of (2S,3S)-2-methylcitrate from propionyl-CoA and oxaloacetate. Plays an important role in detoxification of propionyl-CoA, an inhibitor of both primary and secondary metabolism. Has also citrate synthase activity using as substrates acetyl-CoA and oxaloacetate. Plays a key role in the estabishment of invasive pulmonary aspergillosis. H2O + oxaloacetate + propanoyl-CoA = (2S,3S)-2-methylcitrate + CoA + H(+) acetyl-CoA + H2O + oxaloacetate = citrate + CoA + H(+) Organic acid metabolism; propanoate degradation. Homodimer. Expression is induced by peptone and during infection. Leads to attenuated virulence in a mouse model for pulmonary infection and an infection model based on embryonated eggs. Belongs to the citrate synthase family.