title: Cloning and characterization of a pyridoxine 5'-phosphate oxidase from silkworm, Bombyx mori.
abstract: A cDNA encoding Pyridoxine 5'-phosphate oxidase (PNPO) from Bombyx mori was cloned and characterized (GenBank accession number: DQ452398). The cDNA encodes a polypeptide of 257 amino acid residues. The recombinant enzyme purified from Escherichia coli exhibited maximal activity at pH 9.0, and the K(m) values for the substrates of pyridoxine 5'-phosphate and pyridoxamine 5'-phosphate were determined as 0.65 and 1.15 micromol/l. It was found that B. mori PNPO shares 51.44% homology with humans, but several function-related, key amino acid residues in B. mori PNPO are different from the human and E. Coli gene. B. mori has a single copy of the PNPO gene, which spans a 3.5 kb region and contains five exons and four introns. B. mori PNPO is a homodimer, with each monomer containing nine antiparallel beta-strands and five alpha-helical segments. The secondary structure was deduced from computational study.
authors.affiliation: Anhui Agricultural University, Hefei, People's Republic of China.
authors.forename: S-H
authors.initials: SH
authors.lastname: Huang
authors.forename: R-J
authors.initials: RJ
authors.lastname: Shi
authors.forename: J-Y
authors.initials: JY
authors.lastname: Zhang
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: L-Q
authors.initials: LQ
authors.lastname: Huang
mesh_terms: D000818:Animals; D012831:Bombyx / Q000201:enzymology* / Q000235:genetics; D002417:Cattle; D004926:Escherichia coli / Q000378:metabolism; D049750:Genome, Insect; D006801:Humans; D051379:Mice; D017434:Protein Structure, Tertiary; D011734:Pyridoxaminephosphate Oxidase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D011994:Recombinant Proteins; D011734:Pyridoxaminephosphate Oxidase