title: IS2-43 and IS2-44: new alleles of the insertion sequence IS2 which have promoter activity.
abstract: The sequence of two new IS2 alleles with promoter activity (IS2-43 and IS2-44) is reported. The alleles are identical and are formed by a 17 bp tandem duplication in an AT-rich region of IS2. This created a new RNA polymerase binding site. A mutation was found that increased the frequency of formation of these 17 bp duplications but not of another class of duplications, the "mini-insertions". This suggested that the mechanisms of formation of the two classes of duplications are different.
mesh_terms: D000483:Alleles; D001483:Base Sequence; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000032:analysis*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D009154:Mutation; D009693:Nucleic Acid Hybridization
chemical_list: D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D012321:DNA-Directed RNA Polymerases