1h84

COVALENT ADDUCT BETWEEN POLYAMINE OXIDASE AND N1ethylN11((cycloheptyl)methyl)4,8diazaundecane at pH 4.6

spinqualitylabelsall models 1h84, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1h84 is a 3 chain structure with sequence from Zea mays. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: FAD, FCA, MAN, NAG, NBA Related: 1b37, 1b5q, 1h81, 1h82, 1h83, 1h86 Activity: Oxidoreductase, with EC number 1.5.3.14, 1.5.3.15, 1.5.3.16 and 1.5.3.17 1.5.3.13, 1.5.3.14, 1.5.3.15, 1.5.3.16 and 1.5.3.17 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [PAO_MAIZE] Catalyzes the oxidation of the secondary amino group of polyamines (spermine, spermidine and their acetyl derivatives). Plays an important role in the regulation of polyamine intracellular concentration. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Polyamine oxidase (PAO) carries out the FAD-dependent oxidation of the secondary amino groups of spermidine and spermine, a key reaction in the polyamine catabolism. The active site of PAO consists of a 30 A long U-shaped catalytic tunnel, whose innermost part is located in front of the flavin ring. To provide insight into the PAO substrate specificity and amine oxidation mechanism, we have investigated the crystal structure of maize PAO in the reduced state and in complex with three different inhibitors, guazatine, 1,8-diaminooctane, and N(1)-ethyl-N(11)-[(cycloheptyl)methyl]-4,8-diazaundecane (CHENSpm). In the reduced state, the conformation of the isoalloxazine ring and the surrounding residues is identical to that of the oxidized enzyme. Only Lys300 moves away from the flavin to compensate for the change in cofactor protonation occurring upon reduction. The structure of the PAO.inhibitor complexes reveals an exact match between the inhibitors and the PAO catalytic tunnel. Inhibitor binding does not involve any protein conformational change. Such lock-and-key binding occurs also in the complex with CHENSpm, which forms a covalent adduct with the flavin N5 atom. Comparison of the enzyme complexes hints at an "out-of-register" mechanism of inhibition, in which the inhibitor secondary amino groups are not properly aligned with respect to the flavin to allow oxidation. Except for the Glu62-Glu170 pair, no negatively charged residues are involved in the recognition of substrate and inhibitor amino groups, which is in contrast to other polyamine binding proteins. This feature may be exploited in the design of drugs specifically targeting PAO. Structural bases for inhibitor binding and catalysis in polyamine oxidase.,Binda C, Angelini R, Federico R, Ascenzi P, Mattevi A Biochemistry. 2001 Mar 6;40(9):2766-76. PMID:11258887 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Polyamine oxidase

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