Non-mitochondrial 3-hydroxy-3-methylglutaryl-CoA lyase that catalyzes a cation-dependent cleavage of (S)-3-hydroxy-3- methylglutaryl-CoA into acetyl-CoA and acetoacetate, a key step in ketogenesis, the products of which support energy production in nonhepatic animal tissues. {ECO:0000269|PubMed:22847177, ECO:0000269|PubMed:22865860}. This is the function of HMGCLL1 (3-hydroxy-3-methylglutaryl-CoA lyase like 1, Ensembl gene identifier ENSG00000146151).