A nitrite reductase-hydroxylamine oxidoreductase protein that probably functions in the type 1 encapsulin nanocompartment. Probably involved in reductive catalysis. Targeted to the encapsulin nanocompartment by association with the diheme domain of the encapsulin shell protein (AC Q1Q6L7) (Probable). Catalyzes the reduction of nitrite to nitric oxide (NO) (By similarity). Catalyzes the oxidation of hydroxylamine to nitrite (By similarity). 4 Fe(III)-[cytochrome c] + H2O + hydroxylamine = 4 Fe(II)-[cytochrome c] + 5 H(+) + nitrite Fe(III)-[cytochrome c] + H2O + nitric oxide = Fe(II)-[cytochrome c] + 2 H(+) + nitrite Binds 8 heme groups per subunit. In (PubMed:28263314) the construct expressed anaerobically in E.coli contains only the nitrite reductase domain (residues 28-327). In the N-terminal section; belongs to the multicopper oxidase family.