This entry includes pyridoxamine 5'-phosphate oxidases, FMN flavoproteins that catalyse the oxidation of pyridoxamine-5-P (PMP) and pyridoxine-5-P (PNP) to pyridoxal-5-P (PLP). This reaction serves as the terminal step in the de novo biosynthesis of ...
This entry includes pyridoxamine 5'-phosphate oxidases, FMN flavoproteins that catalyse the oxidation of pyridoxamine-5-P (PMP) and pyridoxine-5-P (PNP) to pyridoxal-5-P (PLP). This reaction serves as the terminal step in the de novo biosynthesis of PLP in Escherichia coli and as a part of the salvage pathway of this coenzyme in both E. coli and mammalian cells [1-5]. The binding sites for FMN and for substrate have been highly conserved throughout evolution. In some species, the coenzyme F420 may perform the FMN role [7]. This entry represents the N-terminal segment of these proteins, which is involved in FMN binding when they form the dimer [5]. In human PNPO, it has been shown that this region contains some of the residues that constitute the PLP allosteric site which regulates its activity [4]. The C-terminal region of these proteins (Pfam:PF10590) is involved in dimerisation and also contributes some residues to the PLP allosteric site. Some of the members included in this entry are involved in phenazine biosynthesis [6].