title: Analysis of Tn3 sequences required for transposition and immunity.
abstract: Tn3 is a 5-kb transposon (Tn) with 38-bp inverted terminal repeats (ITR). The two 38-bp terminal sequences are required in cis for Tn3 transposition. In this study, the role of the ITR in Tn3 transposition has been further dissected by the use of various mini-Tn3 Tn's. The transposition frequency of these mini-Tn's demonstrate that Tn3 contains no sequence other than the ITR sequences that are necessary for the first step in transposition; the two terminal repeats must be oriented as ITR for transposition to occur; the outside 34 bp of the ITR are required for transposition; and reducing the distance between the terminal sequences does not affect transposition frequency. Moreover, mutant copies of the ITR sequences that cannot function in transposition do not confer transposition immunity.
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D002872:Chromosome Deletion; D004262:DNA Restriction Enzymes; D004251:DNA Transposable Elements; D007109:Immunity; D010957:Plasmids; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D004251:DNA Transposable Elements; D004262:DNA Restriction Enzymes