Molecular function

Catalysis of the reaction: acetoacetyl-CoA + acetyl-CoA + H2O = (S)-3-hydroxy-3-methylglutaryl-CoA + CoA + H+.

(S)-3-hydroxy-3-methylglutaryl-CoA acetoacetyl-CoA-lyase (CoA-acetylating), (s)-3-hydroxy-3-methylglutaryl-CoA acetoacetyl-CoA-lyase (CoA- acetylating) activity, 3-hydroxy-3-methylglutaryl CoA synthetase activity, 3-hydroxy-3-methylglutaryl coenzyme A synthase activity, 3-hydroxy-3-methylglutaryl coenzyme A synthetase activity, 3-hydroxy-3-methylglutaryl-CoA synthase activity, 3-hydroxy-3-methylglutaryl-coenzyme A synthase activity, HMG-CoA synthase activity, acetoacetyl coenzyme A transacetase activity, acetyl-CoA:acetoacetyl-CoA C-acetyltransferase (thioester-hydrolysing, carboxymethyl-forming), beta-hydroxy-beta-methylglutaryl-CoA synthase activity, hydroxymethylglutaryl coenzyme A synthase activity, hydroxymethylglutaryl coenzyme A-condensing enzyme, hydroxymethylglutaryl coenzyme alpha-condensing enzyme activity

Note that this function was formerly EC:4.1.3.5.