acetyl-CoA + H2O + oxaloacetate = citrate + CoA + H(+) Weakly inhibited by ATP (apparent Ki = 10 mm). Carbohydrate metabolism; tricarboxylic acid cycle; isocitrate from oxaloacetate: step 1/2. Homohexamer. Citrate synthase is found in nearly all cells capable of oxidative metabolism. Belongs to the citrate synthase family.