title: A repressor heterodimer binds to a chimeric operator.
abstract: Replacement of the solvent-exposed residues of the DNA recognition helix of the 434 repressor with the corresponding residues of the P22 repressor generates a hybrid protein, 434R[alpha 3(P22R)], which binds specifically to P22 operators. We show here that a new DNA-binding specificity is generated by combining 434 and 434R[alpha 3(P22R)] repressor monomers to form a heterodimer. The heterodimer specifically recognizes a chimeric P22/434 operator that lacks two-fold rotational symmetry.
authors.affiliation: Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, MA 02138.
authors.forename: M
authors.initials: M
authors.lastname: Hollis
authors.forename: D
authors.initials: D
authors.lastname: Valenzuela
authors.forename: D
authors.initials: D
authors.lastname: Pioli
authors.forename: R
authors.initials: R
authors.lastname: Wharton
authors.forename: M
authors.initials: M
authors.lastname: Ptashne
mesh_terms: D001483:Base Sequence; D003850:Deoxyribonuclease I / Q000494:pharmacology; D009154:Mutation; D009875:Operator Regions, Genetic; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D012097:Repressor Proteins; D014157:Transcription Factors; D003850:Deoxyribonuclease I