Involved in the catatabolism of testosterone. Catalyzes the hydration of 2-hydroxyhexa-2,4-dienoic acid to 4-hydroxy-2-oxohexanoic acid. (2Z,4Z)-2-hydroxyhexa-2,4-dienoate + H2O = 4-hydroxy-2-oxohexanoate Belongs to the hydratase/decarboxylase family.