Inverted repeats of Tn5 are transposable elements.

Experiments presented here show that each of the 1.5-kilobase inverted repeats of the kanamycin-resistance transposon Tn5 is transposable; we designate them IS50-L (left) and IS50-R (right). By DNA sequence analyses, IS50 is 1533 base pairs (bp) long and generates 9-bp direct repeats of target sequences. The ends of IS50 comprise a hyphenated 8-of-9-bp inverted repeat and are not used with equal efficiency; the outside ends are more active than the inside ends, suggesting that a strong transposase recognition site at the outside ends, suggesting that a strong transposase recognition site at the outside end extends beyond the 8 bp common to both ends.