A flavoprotein (FMN). In Escherichia coli, the coenzyme pyridoxal 5'-phosphate is synthesized de novo by a pathway that involves EC 188.8.131.52
(erythrose-4-phosphate dehydrogenase), EC 184.108.40.2060
(4-phosphoerythronate dehydrogenase), EC 220.127.116.11
(phosphoserine transaminase), EC 18.104.22.1682
(4-hydroxythreonine-4-phosphate dehydrogenase), EC 22.214.171.124
(pyridoxine 5'-phosphate synthase) and EC 126.96.36.199
(with pyridoxine 5'-phosphate as substrate). N4'-Substituted pyridoxamine derivatives are also oxidized in reaction (1) to form pyridoxal 5-phosphate and the corresponding primary amine.