Catalyzes the hydrolysis of 2-hydroxy-6-oxohepta-2,4-dienoate into 2-hydroxypenta-2,4-dienoate and acetate. (2Z,4E)-2-hydroxy-6-oxohepta-2,4-dienoate + H2O = (2Z)-2-hydroxypenta-2,4-dienoate + acetate + H(+) Xenobiotic degradation; toluene degradation. Belongs to the DmpD/TodF/XylF esterase family.