J. Biol. Chem., Vol. 267, Issue 31, 22587-22594, Nov, 1992
Functional domains of aromatase cytochrome P450 inferred from comparative analyses of amino acid sequences and substantiated by site- directed mutagenesis experiments [published erratum appears in J Biol Chem 1994 Jan 14;269(2):1564]
S Chen and D Zhou
Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, California 91010.
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.