title: Transcriptional regulation and gene arrangement of Escherichia coli, Citrobacter freundii and Salmonella typhimurium biotin operons.
abstract: The bio operons of Citrobacter freundii and Escherichia coli K-12 (strain C600) were isolated by screening lambda banks for complementation of E. coli bio mutants. These were compared with the previously isolated bio operon of Salmonella typhimurium and previous data on E. coli K-12. The restriction maps of the operon are very different in the three species, but no difference in gene order was found. Operator-promoter DNA, identified by repressible titration and by biotin-repressible transcription in E. coli, was sequenced and compared to the published E. coli K-12 sequence. In the segment previously identified as operator/bioB promoter, C. freundii and S. typhimurium DNA are identical and differ from E. coli only by 2 bp. The DNA to the right of this segment (indicated by previous data to be the bioA promoter of E. coli) has diverged in all three species, and only E. coli has a sequence resembling a consensus promoter.
authors.affiliation: Department of Biological Sciences, Stanford University, CA 94305.
authors.forename: D
authors.initials: D
authors.lastname: Shiuan
authors.forename: A
authors.initials: A
authors.lastname: Campbell
mesh_terms: D010582:Bacteriophage lambda / Q000235:genetics; D001483:Base Sequence; D001710:Biotin / Q000235:genetics*; D002954:Citrobacter / Q000235:genetics; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D005809:Genes, Regulator; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D009876:Operon; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins; D015183:Restriction Mapping; D012486:Salmonella typhimurium / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
chemical_list: D012097:Repressor Proteins; D001710:Biotin; D004247:DNA