2bvf: Difference between revisions
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==Overview== | ==Overview== | ||
The crystal structure of 6-hydroxy-d-nicotine oxidase (EC 1.5.3.6) was, solved by X-ray diffraction analysis in three crystal forms at resolutions, up to 1.9 A. The enzyme is monomeric in solution and also in the mother, liquor but formed disulfide-dimers in all crystals. It belongs to the, p-cresol methylhydroxylase-vanillyl-alcohol oxidase family and contains an, FAD covalently bound to the polypeptide. The covalent bond of this enzyme, was the first for which a purely autocatalytic formation had been shown., In contrast to previous reports, the bond does not involve N(epsilon2), (N3) of His72 but the N(delta1) (N1) atom. The geometry of this reaction, is proposed and the autoflavinylation is discussed in the light of, homologous structures. The enzyme is specific for ... | The crystal structure of 6-hydroxy-d-nicotine oxidase (EC 1.5.3.6) was, solved by X-ray diffraction analysis in three crystal forms at resolutions, up to 1.9 A. The enzyme is monomeric in solution and also in the mother, liquor but formed disulfide-dimers in all crystals. It belongs to the, p-cresol methylhydroxylase-vanillyl-alcohol oxidase family and contains an, FAD covalently bound to the polypeptide. The covalent bond of this enzyme, was the first for which a purely autocatalytic formation had been shown., In contrast to previous reports, the bond does not involve N(epsilon2), (N3) of His72 but the N(delta1) (N1) atom. The geometry of this reaction, is proposed and the autoflavinylation is discussed in the light of, homologous structures. The enzyme is specific for 6-hydroxy-D-nicotine and, is inhibited by the L-enantiomer. This observation was verified by, modeling enzyme-substrate and enzyme-inhibitor complexes, which also, showed the geometry of the catalyzed reaction. The binding models, indicated that the deprotonation of the substrate rather than the hydride, transfer is the specificity-determining step. The functionally closely, related 6-hydroxy-L-nicotine oxidase processing the L-enantiomer is, sequence-related to the greater glutathione reductase family with quite a, different chainfold. A model of this "sister enzyme" derived from known, homologous structures suggests that the reported L-substrate specificity, and D-enantiomer inhibition are also determined by the location of the, deprotonating base. | ||
==About this Structure== | ==About this Structure== | ||
2BVF is a | 2BVF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arthrobacter_nicotinovorans Arthrobacter nicotinovorans] with FAD as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/(R)-6-hydroxynicotine_oxidase (R)-6-hydroxynicotine oxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.5.3.6 1.5.3.6] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BVF OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: oxidase]] | [[Category: oxidase]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 14:24:31 2007'' | ||
