1dnl: Difference between revisions

[[Image:1dnl.jpg|left|200px]]<br /><applet load="1dnl" size="350" color="white" frame="true" align="right" spinBox="true"  

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.

1DNL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=FMN:'>FMN</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Pyridoxal_5'-phosphate_synthase Pyridoxal 5'-phosphate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.4.3.5 1.4.3.5] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DNL OCA].  

[[Category: Abraham, D J.]]

[[Category: Musayev, F N.]]

[[Category: Safo, M K.]]

[[Category: Salvo, M L.di.]]

[[Category: Thiel, D J.]]

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