BuT2 is a member of the third major group of hAT transposons and is involved in horizontal transfer events in the genus Drosophila.

The hAT superfamily comprises a large and diverse array of DNA transposons found in all supergroups of eukaryotes. Here we characterized the Drosophila buzzatii BuT2 element and found that it harbors a five-exon gene encoding a 643-aa putatively functional transposase. A phylogeny built with 85 hAT transposases yielded, in addition to the two major groups already described, Ac and Buster, a third one comprising 20 sequences that includes BuT2, Tip100, hAT-4_BM, and RP-hAT1.