label: 4-carboxymethyl-4-methylbutenolide mutase activity
label_lc: 4-carboxymethyl-4-methylbutenolide mutase activity
description: "Catalysis of the reaction: 4-carboxymethyl-4-methylbut-2-en-1,4-olide = 4-carboxymethyl-3-methylbut-2-en-1,4-olide."