This alignment model represents the N-terminal rieske domain of the oxygenase alpha subunit (DitA) of diterpenoid dioxygenase (DTDO). DTDO is a novel aromatic-ring-hydroxylating dioxygenase found in Pseudomonas and other proteobacteria that degrades dehydroabietic acid (DhA). Specifically, DitA hydroxylates 7-oxodehydroabietic acid to 7-oxo-11,12-dihydroxy-8, 13-abietadien acid. The ditA1 and ditA2 genes encode the alpha and beta subunits of the oxygenase component of DTDO while the ditA3 gene encodes the ferredoxin component of DTDO. The organization of the genes encoding the various diterpenoid dioxygenase components, the phylogenetic distinctiveness of both the alpha subunit and the ferredoxin component, and the unusual iron-sulfur cluster of the ferredoxin all suggest that this enzyme belongs to a new class of aromatic ring-hydroxylating dioxygenases.