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1dnl
From Proteopedia
X-RAY STRUCTURE OF ESCHERICHIA COLI PYRIDOXINE 5'-PHOSPHATE OXIDASE COMPLEXED WITH FMN AT 1.8 ANGSTROM RESOLUTION
Overview
BACKGROUND: Escherichia coli pyridoxine 5'-phosphate oxidase (PNPOx) catalyzes the terminal step in the biosynthesis of pyridoxal 5'-phosphate (PLP), a cofactor used by many enzymes involved in amino acid metabolism. The enzyme oxidizes either the 4'-hydroxyl group of pyridoxine 5'-phosphate (PNP) or the 4'-primary amine of pyridoxamine 5'-phosphate (PMP) to an aldehyde. PNPOx is a homodimeric enzyme with one flavin mononucleotide (FMN) molecule non-covalently bound to each subunit. A high degree of sequence homology among the 15 known members of the PNPOx family suggests that all members of this group have similar three-dimensional folds. RESULTS: The crystal structure of PNPOx from E. coli has been determined to 1.8 A resolution. The monomeric subunit folds into an eight-stranded beta sheet surrounded by five alpha-helical structures. Two monomers related by a twofold axis interact extensively along one-half of each monomer to form the dimer. There are two clefts at the dimer interface that are symmetry-related and extend from the top to the bottom of the dimer. An FMN cofactor that makes interactions with both subunits is located in each of these two clefts. CONCLUSIONS: The structure is quite similar to the recently deposited 2.7 A structure of Saccharomyces cerevisiae PNPOx and also, remarkably, shares a common structural fold with the FMN-binding protein from Desulfovibrio vulgaris and a domain of chymotrypsin. This high-resolution E. coli PNPOx structure permits predictions to be made about residues involved in substrate binding and catalysis. These predictions provide testable hypotheses, which can be answered by making site-directed mutants.
About this Structure
1DNL is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
X-ray structure of Escherichia coli pyridoxine 5'-phosphate oxidase complexed with FMN at 1.8 A resolution., Safo MK, Mathews I, Musayev FN, di Salvo ML, Thiel DJ, Abraham DJ, Schirch V, Structure. 2000 Jul 15;8(7):751-62. PMID:10903950 Page seeded by OCA on Fri May 2 14:03:21 2008
