Members of this protein family, 3,5/4-trihydroxycyclohexa-1,2-dione hydrolase (iolD), represent one of eight enzymes in a pathway converting myo-inositol to acetyl-CoA. IolD hydrolyzes the cyclic molecule 3D-(3,5/4)-trihydroxycyclohexane-1,2-dione to yield 5-deoxy-D-glucuronic acid. TPP is a cofactor. [Energy metabolism, Sugars]