Figure 1.

LEFT Pathway for electron flow from NAD(P)H t to the catalytic dioxygenase. Electron transfer proteins mediating the transfer can include a FMN containing reductase, a plant-type or Rieske type iron sulfur cluster ferredoxin, or a combined FMN and iron sulfur cluster containing reductase. RIGHT General classification scheme for the four classes of ROs as defined by Chakraborty and coworkers. Classification is based on dioxygenase structure and composition of electron transport proteins.