Citrate synthase is an enzyme of the citric acid cycle (and glyoxylate cycle) that catalyzes the condensation of acetyl-CoA and oxaloacetate to form citrate. The reaction is as follows:

Acetyl-CoA + Oxaloacetate + H2O <=> Citrate + CoASH + H⁺ ( = -32.2 kJ/mol)

Citroyl-CoA is an intermediate in the reaction.

Note that the large negative value of this reaction helps to "pull" the highly positive of the reaction preceding it.

Citrate synthase is regulated by availability of substrates - acetyl-CoA and oxaloacetate.

Next enzyme of citric acid cycle / Previous enzyme of cycle

1. Glyoxylate Cycle Metabolism

2. Citric Acid Cycle