1.7.99.1 hydroxylamine reductase - 1.7.99.2 nitric-oxide reductase deleted 1.7.99.3 nitrite reductase deleted, now included with EC 1.7.2.1 1.7.99.4 nitrate reductase transferred to EC 1.7.1.1, nitrate reductase (NADH), EC 1.7.1.2, nitrate reductase [NAD(P)H], EC 1.7.1.3, nitrate reductase (NADPH), EC 1.7.5.1, nitrate reductase (quinone), EC 1.7.7.2, nitrate reductase (ferredoxin), EC 1.9.6.1, nitrate reductase (cytochrome) 1.7.99.5 5,10-methylenetetrahydrofolate reductase (FADH2) deleted, now included with EC 1.5.1.20, methylenetetrahydrofolate reductase [NAD(P)H]. Based on the reference, it had been thought that this was a separate enzyme from EC 1.5.1.20 but the reference upon which the entry was based has since been disproved 1.7.99.6 nitrous-oxide reductase transferred to EC 1.7.2.4 1.7.99.7 nitric-oxide reductase transferred to EC 1.7.2.5 1.7.99.8 hydrazine oxidoreductase transferred to EC 1.7.2.8