Also known as MCAL_RHOS1, mcl1. 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 (By similarity). Homohexamer. Dimer of trimers (By similarity).