Reductase component of the propane 2-monooxygenase multicomponent enzyme system which is involved in the degradation of propane via the O2-dependent hydroxylation of propane (PubMed:14645271). Reductase catalyzes the transfer of electrons from NADH or NADPH to monooxygenase (Probable). Binds 1 2Fe-2S cluster. The propane 2-monooxygenase multicomponent enzyme system is composed of an electron transfer component and a monooxygenase component interacting with the effector protein PrmD. The electron transfer component is composed of a reductase (PrmB), and the monooxygenase component is formed by a large subunit (PrmA) and a small subunit (PrmC). By propane and acetone. Cells lacking this gene are unable to grow on propane and to catalyze the oxidation of phenol to yield hydroquinone. Belongs to the bacterial ring-hydroxylating dioxygenase ferredoxin reductase family.