The enzyme cytochrome c-dependent nitric oxide reductase (cNOR) catalyzes the reduction of nitric oxide into nitrous oxide during microbial denitrification. The binuclear active site of cNOR consists of two iron ions: one heme b₃ iron and one non-heme iron (Fe_B). Interestingly, the Fe_B cofactor requires the metallochaperones NorQ, a AAA+ ATPase, and NorD, a VWA domain protein, for proper insertion. In this thesis, I have characterized NorQ and NorD biochemically and structurally, to reveal that NorQ forms a hexameric ring, binding one copy of NorD in its central pore and that interaction with the cNOR target occurs between NorD and the cytoplasmic surface of cNOR. NorQ is a molecular motor, fueled by ATP hydrolysis and causes conformational changes in NorD. The movements in NorD are further translated into conformational changes in cNOR, enabling iron insertion. In addition, I have identified cNORs that are independent of metallochaperones and compared them to those that are chaperone dependent. The comparison shows that cNORs without chaperones have a water-filled pathway leading from the cytoplasm to the active site, plugged by hydrophobic residues in cNORs with chaperones. This indicates that cNORs without chaperones might be electrogenic and has implications for the evolution of the NOR family.