Abstract
The first heme oxygenase-like dimetal oxidase/oxygenase (HDO) was functionally validated through coordinated spectroscopic and rapid kinetic studies of the fatty acid decarboxylase UndA. The enzyme superfamily has since been recognized to orchestrate a variety of substrate transformations for natural product biosynthesis. In this mini-review, we report on the structures and the catalytic mechanisms of the major HDO subtypes that catalyze carbon-carbon bond cleavage, N-oxygenation, multi-step rearrangements, and radical hole-hopping. A summary of the current status of the field and opportunities for decrypting the molecular basis for the mechanistic divergence of the family are highlighted.