title: Affinity purification and binding characteristics of Citrobacter freundii AmpR, the transcriptional regulator of the ampC beta-lactamase gene.
abstract: The transcriptional regulator of the Citrobacter freundii ampC beta-lactamase gene, AmpR, was purified as a single SDS/PAGE-gel band by using various techniques, including DNA-Sepharose 4B affinity chromatography. The purified AmpR consisted of a 32.5 kDa monomer that interacted with three operator sequences: two binding sequences, at positions -75 to -70 and -67 to -51 with respect to the transcriptional start site, were located in the LysR motif (-72 to -60), and the third sequence was at position -43 to -38. Equilibrium binding studies raise the possibility that the adjacent operator sequence could exert a positive influence on the ability of AmpR to bind to these sites.
authors.affiliation: Department of Biological Science, Korea Advanced Institute of Science and Technology (KAIST), Yusung-gu, Taejon, Korea.
authors.forename: I K
authors.initials: IK
authors.lastname: Roh
authors.forename: I J
authors.initials: IJ
authors.lastname: Kim
authors.forename: J H
authors.initials: JH
authors.lastname: Chung
authors.forename: S M
authors.initials: SM
authors.lastname: Byun
mesh_terms: D001426:Bacterial Proteins; D001483:Base Sequence; D002846:Chromatography, Affinity; D002847:Chromatography, Agarose; D016971:Citrobacter freundii / Q000235:genetics*; D003001:Cloning, Molecular; D018983:DNA Footprinting; D004269:DNA, Bacterial / Q000378:metabolism; D003850:Deoxyribonuclease I; D005798:Genes, Bacterial; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D014158:Transcription, Genetic; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D003850:Deoxyribonuclease I; C048795:AmpC beta-lactamases; D001618:beta-Lactamases