Component of the methylcitrate cycle that catalyzes the dehydration of 2-methylcitrate to 2-methyl-cis-aconitate. The methylcitrate cycle is a metabolic pathway for the consumption of propionic acid. (2S,3S)-2-methylcitrate = 2-methyl-cis-aconitate + H2O Several bivalent metal ions, such as nickel, copper, zinc, mercury, and lead, inhibit the activity to some extent. Inhibited by structural analogs such as citrate, cis-aconitate, isocitrate, 2-methylisocitrate, tricarballylate and fluorocitrate, but not by trans-aconitate or adipate. Optimum pH is 6.5-7.0. Optimum temperature is 25-40 degrees Celsius. Organic acid metabolism; propanoate degradation. Monomer. Slightly repressed by glucose. Leads to lipid accumulation and increased citrate production when biodiesel-derived waste glycerol is used as substrate. Belongs to the PrpD family.