title: Nucleotide sequence for the catalytic domain of colicin E3 and its immunity protein. Evidence for a third gene overlapping colicin.
abstract: We have determined the nucleotide sequence of a segment of Co1E3 DNA coding for the carboxyl-terminal, catalytic peptide of colicin E3 and for the immunity protein. The end of the colicin E3 gene is separated from the beginning of the immunity gene by a nine-basepair intercistronic region, suggesting the two genes are expressed as a single transcriptional unit. The immunity gene is expressed, however, in E. coli strains containing Co1E3-pBR322 hybrid plasmids deleted for the 5'-end of the colicin gene. The DNA sequence also contains an unexpected open reading frame (ORF). This ORF is contained within the colicin gene and is in the +1 reading frame with respect to that gene. Plasmids containing the ORF, directed the synthesis of an 11 kilodalton protein in a cell-free, transcription-translation system.
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001482:Base Composition; D001483:Base Sequence; D003087:Colicins / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005796:Genes; D005798:Genes, Bacterial; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D014176:Protein Biosynthesis; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D003087:Colicins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; C488855:ceiC protein, E coli; C007104:colicin immunity proteins