Required for the assembly of the copper chromophores of nitrous oxide reductase (PubMed:2170125). Could be part of the ABC transporter complex NosDFY (Probable). The complex may be composed of an ATP-binding protein (NosF), a transmembrane protein (NosY) and a solute-binding protein (NosD). Induced in response to denitrifying conditions. Activation requires NosR and DnrD regulators.