title: Tyr-179 and Lys-183 are essential for enzymatic activity of 11 beta-hydroxysteroid dehydrogenase.
abstract: Tyr-179 and Lys-183 are likely to be functionally important residues in 11 beta-hydroxysteroid dehydrogenase, as these amino acids are absolutely conserved in all members of the "short chain dehydrogenase" family. We modified these residues by site-directed mutagenesis of rat cDNA and transfected these constructs into CHO cells. A highly but not absolutely conserved residue, Asp-110, was also studied. Mutation of Tyr-179 to Phe or Ser completely abolished enzymatic activity (interconversion of corticosterone and 11-dehydrocorticosterone), as did Lys-183-->Arg. Asp-110-->Asn affected activity only mildly. Tyr-179 and Lys-183 may be directly involved in the catalytic function of this class of enzymes.
authors.affiliation: Division of Pediatric Endocrinology, Cornell University Medical College, New York, NY 10021.
authors.forename: J
authors.initials: J
authors.lastname: Obeid
authors.forename: P C
authors.initials: PC
authors.lastname: White
mesh_terms: D042842:11-beta-Hydroxysteroid Dehydrogenases; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D006224:Cricetinae; D006913:Hydroxysteroid Dehydrogenases / Q000235:genetics* / Q000378:metabolism*; D007700:Kinetics; D008239:Lysine; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D014162:Transfection; D014443:Tyrosine
chemical_list: D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D014443:Tyrosine; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases; D008239:Lysine