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CYTOCHROME P450 14 ALPHA-STEROL DEMETHYLASE (CYP51) FROM MYCOBACTERIUM TUBERCULOSIS IN FERRIC LOW-SPIN STATE
Structural highlights
FunctionCP51_MYCTU Its precise biological substrate is not known. Catalyzes C14-demethylation of lanosterol, 24,25-dihydrolanosterol and obtusifoliol which is critical for ergosterol biosynthesis. It transforms lanosterol into 4,4'-dimethyl cholesta-8,14,24-triene-3-beta-ol.[1] [2] 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 PubMedSterol 14alpha-demethylases (CYP51) are essential enzymes in sterol biosynthesis in eukaryotes and drug targets in antifungal therapy. Here, we report CYP51 structures in ligand-free and estriol bound forms. Using estriol as a probe, we determined orientation of the substrate in the active site, elucidated protein contacts with the invariant 3beta-hydroxy group of a sterol, and identified F78 as a key discriminator between 4alpha-methylated and 4alpha,beta-dimethylated substrates. Analysis of CYP51 dynamics revealed that the C helix undergoes helix-coil transition upon binding and dissociation of a ligand. Loss of helical structure of the C helix in the ligand-free form results in an unprecedented opening of the substrate binding site. Upon binding of estriol, the BC loop loses contacts with molecular surface and tends to adopt a closed conformation. A mechanism for azole resistance in the yeast pathogen Candida albicans associated with mutations in the ERG11 gene encoding CYP51 is suggested based on CYP51 protein dynamics. Estriol bound and ligand-free structures of sterol 14alpha-demethylase.,Podust LM, Yermalitskaya LV, Lepesheva GI, Podust VN, Dalmasso EA, Waterman MR Structure. 2004 Nov;12(11):1937-45. PMID:15530358[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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