1jip

P450eryF(A245S)/ketoconazole

spinqualitylabelsall models 1jip, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1jip is a 1 chain structure with sequence from Saccharopolyspora erythraea. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2Å Ligands: HEM, KTN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CPXJ_SACEN Catalyzes the NADPH-dependent conversion of 6-deoxyerythronolide B (6-DEB) to erythronolide B (EB) by the insertion of an oxygen at the 6S position of 6-DEB. Requires the participation of a ferredoxin and a ferredoxin reductase for the transfer of electrons from NADPH to the monooxygenase. 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 The azole-based P450 inhibitor ketoconazole is used to treat fungal infections and functions by blocking ergosterol biosynthesis in yeast. Ketoconazole binds to mammalian P450 enzymes and this can result in drug-drug interactions and lead to liver damage. To identify protein-drug interactions that contribute to binding specificity and affinity, we determined the crystal structure of ketoconazole complexed with P450eryF. In the P450eryF/ketoconazole structure, the azole moiety and nearby rings of ketoconzole are positioned in the active site similar to the substrate, 6-deoxyerythronolide B, with the azole nitrogen atom coordinated to the heme iron atom. The remainder of the ketoconazole molecule extends into the active-site pocket, which is occupied by water in the substrate complex. Binding of ketoconazole led to unexpected conformational changes in the I-helix. The I-helix cleft near the active site has collapsed with a helical pitch of 5.4 A compared to 6.6 A in the substrate complex. P450eryF/ketoconazole crystals soaked in 6-deoxyerythronolide B to exchange ligands exhibit a structure identical with that of the original P450eryF/substrate complex, with the I-helix cleft restored to a pitch of 6.6 A. These findings indicate that the I-helix region of P450eryF is flexible and can adopt multiple conformations. An improved understanding of the flexibility of the active-site region of cytochrome P450 enzymes is important to gain insight into determinants of ligand binding/specificity as well as to evaluate models for catalytic mechanism based on static crystal structures. Ketoconazole-induced conformational changes in the active site of cytochrome P450eryF.,Cupp-Vickery JR, Garcia C, Hofacre A, McGee-Estrada K J Mol Biol. 2001 Aug 3;311(1):101-10. PMID:11469860 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome P450 3D structures

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