title: Structure and regulation of gene expression of a Clo DF13 plasmid DNA region involved in plasmid segregation and incompatibility.
abstract: The bacteriocinogenic plasmid Clo DF13 contains genetic information involved in the accurate partitioning of the plasmid (parA and parB) as well as in incompatibility phenomena (incA, B, C and D). In this paper we report on the primary structure and regulation of gene expression of the 29% - 50% part of Clo DF13, containing the DNA regions incA, incB and parB as well as genes K and L. According to the results of our DNA sequence analysis, mapping of transposon insertions, RNA blotting and S1 mapping experiments, we conclude that: a) genes K and L are transcribed as one operon; transcription of this operon is initiated at a promoter (P2) located at 32.5% and proceeds in a clockwise direction. b) treatment of cells with mitomycin-C, significantly enhances transcription from P2, although this promoter is probably not directly repressed by lexA protein. c) Termination of transcription of this operon occurs between genes K and L, as well as distal to gene L. The possible role of gene products and/or sites, located within the 29-50% DNA region, in plasmid incompatibility and segregation is discussed.
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000235:genetics*; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D004251:DNA Transposable Elements; D004720:Endonucleases; D004926:Escherichia coli / Q000235:genetics*; D005796:Genes; D005798:Genes, Bacterial; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014158:Transcription, Genetic
chemical_list: D001430:Bacteriocins; D004251:DNA Transposable Elements; D004720:Endonucleases; D004262:DNA Restriction Enzymes; D015719:Single-Strand Specific DNA and RNA Endonucleases