Nitrite reductase system involved in the terminal oxidation of the Streptomyces griseus respiratory particle.

A nitrite reductase system which was associated with the electron transfer system of the respiratory particle in Streptomyces griseus was studied. The electron transfer pathway consisted of the cytochrome oxidase and the nitrite reductase systems under aerobic and anaerobic conditions respectively, and these systems showed the exact opposite response to 2-n-heptyl-4-hydroxyquinoline-N-oxide and azide. Azide inhibited specifically the nitrite reductase system. It seems that cytochrome d works as the nitrite reductase and the reduced cytochrome b works as an intermediate electron donor for cytochrome d respectively. The respiratory particle also had a hydroxylamine reductase activity and ammonia was identified as the product of hydroxylamine reduction by the respiratory particle. A terminal electron transfer pathway in Streptomyces griseus was proposed.