Involved in the ethylmalonyl-CoA pathway for acetate assimilation. Catalyzes the reversible condensation of glyoxylate and acetyl-CoA to L-malyl-CoA and the reversible condensation of glyoxylate and propionyl-CoA to yield beta-methylmalyl-CoA. It is also able to catalyze the cleavage of (S)-citramalyl-CoA to yield acetyl-CoA and pyruvate, although this reaction is not involved in the ethylmalonyl-CoA pathway. (S)-malyl-CoA = acetyl-CoA + glyoxylate (2R,3S)-beta-methylmalyl-CoA = glyoxylate + propanoyl-CoA (3S)-citramalyl-CoA = acetyl-CoA + pyruvate Divalent cations such as magnesium or manganese. Inhibited by EDTA. Homohexamer. Dimer of trimers. By growth on acetate. Belongs to the HpcH/HpaI aldolase family.