Transposase proteins are necessary for efficient DNA transposition. This domain is a member of the DDE superfamily, which contains three carboxylate residues that are believed to be responsible for coordinating metal ions needed for catalysis. The catalytic activity of this enzyme involves DNA cleavage at a specific site followed by a strand transfer reaction [3].

1: The sequence of IS4. Klaer R, Kuhn S, Tillmann E, Fritz HJ, Starlinger P; Mol Gen Genet 1981;181:169-175. PMID:6268937

2: IS421, a new insertion sequence in Escherichia coli. Sato S, Nakada Y, Shiratsuchi A; FEBS Lett 1989;249:21-26. PMID:2542093

3: Identification and analysis of the gas vesicle gene cluster on an unstable plasmid of Halobacterium halobium. DasSarma S; Plasmid 1993;29:1-9. PMID:8335077