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. May play a role in virulence. H2O + oxaloacetate + propanoyl-CoA = (2S,3S)-2-methylcitrate + CoA + H(+) acetyl-CoA + H2O + oxaloacetate = citrate + CoA + H(+) Optimum pH is 8.0-9.0. Optimum temperature is 50-60 degrees Celsius. Organic acid metabolism; propanoate degradation. Homodimer. Highly expressed in conidia. Leads to the inability to grow on propionate as the sole carbon source, a strong reduction of growth rate and spore color formation on media containing both glucose and propionate, and an accumulation of propionyl-CoA. Leads also to an attenuation of virulence in an insect infection model. Belongs to the citrate synthase family.