title: The LexA protein does not bind specifically to the two SOS box-like sequences immediately 5' to the phr gene.
abstract: There are two SOS box-like sequences located at the regions -161 to -142 and -69 to -50 with regard to the initiation codon of phr. Ihara et al. (1987) constructed a phr'-'lacZ fusion plasmid in which these sequences and the amino terminal end of the phr gene was fused to lacZ and therefore lacZ was under the regulatory control of phr promoter-operator. The authors found that in cells carrying this plasmid beta-galactosidase was inducible by UV and UV-mimetic agents and concluded that phr was controlled by the LexA repressor. We wished to confirm these results by theoretical analysis of the SOS-like sequences by the method developed by Berg (1987) as well as by measuring the binding of LexA protein to the putative SOS boxes by a novel gel retardation assay. Both theoretical analysis and experimental results indicate that the putative SOS boxes immediately 5' to phr have no specific affinity for LexA protein.
authors.affiliation: University of North Carolina, School of Medicine, Department of Biochemistry, Chapel Hill 27599.
authors.forename: N S
authors.initials: NS
authors.lastname: Payne
authors.forename: A
authors.initials: A
authors.lastname: Sancar
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D004260:DNA Repair; D004269:DNA, Bacterial / Q000378:metabolism*; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial / Q000187:drug effects / Q000528:radiation effects; D007763:Lac Operon; D008190:Lyases / Q000235:genetics*; D012097:Repressor Proteins / Q000378:metabolism*; D013014:SOS Response, Genetics; D012697:Serine Endopeptidases; D014157:Transcription Factors / Q000378:metabolism*; D014466:Ultraviolet Rays; D001616:beta-Galactosidase / Q000235:genetics; D000099160:LexA Repressor Protein
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004255:Deoxyribodipyrimidine Photo-Lyase; D008190:Lyases; D012097:Repressor Proteins; D012697:Serine Endopeptidases; D014157:Transcription Factors; D001616:beta-Galactosidase; D000099160:LexA Repressor Protein