Involved in iodate respiration (PubMed:32190953). Probably catalyzes the reduction of iodate (IO(3)(-)) to hypoiodous acid (HIO) and H(2)O(2), using a reduced cytochrome c as the electron donor (PubMed:32190953). Binds 1 [3Fe-4S] cluster per subunit. Binds 1 molybdenum-bis(molybdopterin guanine dinucleotide) (Mo-bis-MGD) cofactor per subunit. The iodate reductase (Idr) complex is composed of a molybdopterin-dependent iodate reductase (IdrA and IdrB subunits) and two associated peroxidases (IdrP1 and IdrP2). Abundantly expressed under iodate-respiring conditions. Belongs to the prokaryotic molybdopterin-containing oxidoreductase family.