title: Molecular characterization of a DNA fragment carrying the basic replicon of pTUC100, the natural plasmid encoding the peptide antibiotic microcin J25 system.
abstract: The Escherichia coli plasmid pTUC100 encodes production of, and immunity to, the peptide antibiotic microcin J25. In the present study, an approximately 8-kb fragment immediately adjacent to the previously sequenced microcin region was isolated and its DNA sequence was determined. The main features of the newly characterized region are: (i) a basic replicon which is almost identical to that of the RepFIIA plasmid R100; (ii) two ORFs with 96% identity to two ORFs of unknown function on pO157, a large plasmid harbored by enterohemorragic E. coli, and a large ORF which does not show significant homology to any other reported nucleotide or protein sequence; and (iii) two intact insertion sequences, IS1294 and IS1. Sequence analysis, as well as that of the G+C content of both the 8-kb fragment and the previously sequenced microcin locus, lead us to propose that plasmid pTUC100 is a composite structure assembled from DNA elements from various sources.
authors.affiliation: Departamento de Bioquímica de la Nutrición, Instituto Superior de Investigaciones Biológicas ,Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad Nacional de Tucumán, Tucumán, Argentina.
authors.forename: Mónica A
authors.initials: MA
authors.lastname: Delgado
authors.forename: Raúl A
authors.initials: RA
authors.lastname: Salomón
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D001430:Bacteriocins; D002876:Chromosomes, Bacterial; D003001:Cloning, Molecular; D003596:Cytosine / Q000032:analysis; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D006147:Guanine / Q000032:analysis; D016254:Mutagenesis, Insertional; D016366:Open Reading Frames; D010455:Peptides; D020161:Physical Chromosome Mapping; D010957:Plasmids / Q000235:genetics*; D012093:Replicon; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D010455:Peptides; C020411:microcin; D006147:Guanine; D003596:Cytosine