Functional domains of aromatase cytochrome P450 inferred from comparative analyses of amino acid sequences and substantiated by site-directed mutagenesis experiments.
Several functional domains, especially the active site regions, in aromatase cytochrome P450 were inferred by alignment of amino acid sequences of the enzyme from five species, human, rat, mouse, chicken, and trout, and that of Pseudomonas putida cytochrome P450cam, whose x-ray structure has been determined (Poulos, T.L., Finzel, B.C., and Howard, A.J. (1987) J. Mol. Biol. 195, 687-700). The predicted functions of these domains have been evaluated by site-directed mutagenesis. Eighteen mutants, including seven new mutants, have been generated in this laboratory. The seven newly prepared mutants are Q123E, Q123H, T310S, T310C, R365K, R365A, and N delta 20 (a mutant without the first 20 amino acids). The preparation and characterization of these new mutants are described. The structural model described in this paper should be very useful for future structure-function studies of aromatase by site-directed mutagenesis.
Chen
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Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, California 91010.
Zhou
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D000595:Amino Acid Sequence; D000818:Animals; D001141:Aromatase / Q000737:chemistry*; D001483:Base Sequence; D001665:Binding Sites; D002645:Chickens; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D005091:Exons; D005796:Genes; D006418:Heme / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D016958:Pseudomonas putida; D051381:Rats; D016415:Sequence Alignment; D012995:Solubility; D013329:Structure-Activity Relationship; D014337:Trout
D008565:Membrane Proteins; D006418:Heme; D003577:Cytochrome P-450 Enzyme System; D001141:Aromatase