Function
Catalyzes the last step of the bacterial protocatechuate 4,5-cleavage pathway. Has a broad substrate specificity and catalyzes the aldol cleavage of 4-hydroxy-4-methyl-2-oxoglutarate, 4-hydroxy-2-oxoglutarate and 4-carboxy-4-hydroxy-2-oxoadipate, and the decarboxylation of oxaloacetate. Preferentially cleaves the L-isomer of 4-carboxy-4-hydroxy-2-oxoadipate, and has lower activity towards 4-hydroxy-4-methyl-2-oxoglutarate and 4-Hydroxy-2-oxoglutarate. Does not cleave 4-hydroxy-2-oxovalerate, citrate, 4-hydroxy-2-oxobutyrate, 2-oxoglutarate or fructose-1,6-bisphosphate.