Mitochondrial citramalyl-CoA lyase indirectly involved in the vitamin B12 metabolism. Converts citramalyl-CoA into acetyl-CoA and pyruvate in the C5-dicarboxylate catabolism pathway. The C5-dicarboxylate catabolism pathway is required to detoxify itaconate, a vitamin B12-poisoning metabolite. Also acts as a malate synthase in vitro, converting glyoxylate and acetyl-CoA to malate. Also displays malyl-CoA thioesterase activity. Also acts as a beta-methylmalate synthase in vitro, by mediating conversion of glyoxylate and propionyl-CoA to beta-methylmalate. Also has very weak citramalate synthase activity in vitro. acetyl-CoA + glyoxylate + H2O = (S)-malate + CoA + H(+) glyoxylate + H2O + propanoyl-CoA = 3-methylmalate + CoA + H(+) (3S)-citramalyl-CoA = acetyl-CoA + pyruvate (S)-malyl-CoA + H2O = (S)-malate + CoA + H(+) Binds 1 Mg(2+) ion per subunit. Homotrimer. Belongs to the HpcH/HpaI aldolase family. Citrate lyase beta subunit-like subfamily. This organism lacks the other subunits that are necessary for ATP-independent citrate lyase activity. Even though this protein has clear similarity to citrate lyase beta subunit, it is expected to have a somewhat different enzyme activity.