title: Mutant lac repressors with new specificities hint at rules for protein--DNA recognition.
abstract: Proteins which recognize specific sequences of DNA play a fundamental role in the regulation of protein synthesis in all organisms. A particular helix of the bacterial protein lac repressor recognizes the bases in the major groove of the lac operator. We show that the first two residues of this recognition helix interact independently with two base pairs. This allows us in many cases to predict repression as an indicator of strength of the repressor-operator complex. Rules of recognition can be derived for 16 symmetric operators. They also apply to the gal repressor and possibly to other bacterial repressors.
authors.affiliation: Institut für Genetik, Universität zu Köln, FRG.
authors.forename: N
authors.initials: N
authors.lastname: Lehming
authors.forename: J
authors.initials: J
authors.lastname: Sartorius
authors.forename: B
authors.initials: B
authors.lastname: Kisters-Woike
authors.forename: B
authors.initials: B
authors.lastname: von Wilcken-Bergmann
authors.forename: B
authors.initials: B
authors.lastname: Müller-Hill
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics; D007763:Lac Operon; D008969:Molecular Sequence Data; D009154:Mutation; D011487:Protein Conformation; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D012097:Repressor Proteins; D014157:Transcription Factors