title: Detection of free cytoplasmic circles of transposon Tn9 multimers in Escherichia coli.
abstract: Extrachromosomal circular DNA molecules consisting of IS1-cat repeats, (IS1-cat)n, were isolated from an E. coli strain harboring nearly 30 copies of tandemly amplified transposon Tn9 located on the chromosome. The DNA 'circles' were characterized by restriction analysis followed by Southern blotting and electron microscopic examination. Their size varied from approximately 5.5 kb to 53 kb.
authors.affiliation: Molecular Biology & Agriculture Division, Bhabha Atomic Research Centre, Bombay, India.
authors.forename: J F
authors.initials: JF
authors.lastname: Sarkari
authors.forename: S K
authors.initials: SK
authors.lastname: Mahajan
mesh_terms: D015139:Blotting, Southern; D004251:DNA Transposable Elements; D004270:DNA, Circular / Q000032:analysis / Q000302:isolation & purification* / Q000648:ultrastructure; D004926:Escherichia coli / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D011815:R Factors / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D004270:DNA, Circular