Structure and properties of recombinant human pyridoxine 5'-phosphate oxidase.
Pyridoxine 5'-phosphate oxidase catalyzes the terminal step in the synthesis of pyridoxal 5'-phosphate. The cDNA for the human enzyme has been cloned and expressed in Escherichia coli. The purified human enzyme is a homodimer that exhibits a low catalytic rate constant of approximately 0.2 sec(-1) and K(m) values in the low micromolar range for both pyridoxine 5'phosphate and pyridoxamine 5'-phosphate. Pyridoxal 5'-phosphate is an effective product inhibitor. The three-dimensional fold of the human enzyme is very similar to those of the E. coli and yeast enzymes. The human and E. coli enzymes share 39% sequence identity, but the binding sites for the tightly bound FMN and substrate are highly conserved. As observed with the E. coli enzyme, the human enzyme binds one molecule of pyridoxal 5'-phosphate tightly on each subunit.
Musayev
Faik N
FN
Department of Medicinal Chemistry, Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, 800 E. Leigh Street, Richmond, VA 23219, USA.
Di Salvo
Martino L
ML
Ko
Tzu-Ping
TP
Schirch
Verne
V
Safo
Martin K
MK
D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005486:Flavin Mononucleotide / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D011732:Pyridoxal Phosphate / Q000378:metabolism; D011734:Pyridoxaminephosphate Oxidase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment
D011994:Recombinant Proteins; D011732:Pyridoxal Phosphate; D005486:Flavin Mononucleotide; D011734:Pyridoxaminephosphate Oxidase