4-hydroxymuconic semialdehyde dehydrogenase (HapE, EC=1.2.1.61) of Pseudomonas fluorescens ACB involved in 4-hydroxyacetophenone degradation, and putative hydroxycaproate semialdehyde dehydrogenase (ChnE) of Brachymonas petroleovorans involved in cyclohexane metabolism, and other similar sequences, are present in this CD.