Two alternative routes for maleylpyruvate catabolism in the gentisate pathway. GDO, gentisate 1,2-dioxygenase (HbzE in strain SponMu) (19); MPH, maleylpyruvate hydrolase (HbzF in strain SponMu) (10); MH, maleate hydratase (HbzIJ in strain SponMu) (this study); DMDH, d-malate dehydrogenase; MPI, maleylpyruvate isomerase (HbzG in strain SponMu) (this study); FPH, fumarylpyruvate hydrolase.