Transposons are mobile DNA sequences capable of replication and insertion into the chromosome. Typically transposons code for the transposase enzyme, which catalyses insertion, found between terminal inverted repeats. Tn5 has a unique method of self- regulation in which a truncated version of the transposase enzyme acts as an inhibitor [1]. The catalytic domain of the Tn5 transposon is found in Pfam:PF01609. This domain mediates dimerisation in the known structure.

1: The three-dimensional structure of a Tn5 transposase-related protein determined to 2.9-A resolution. Davies DR, Braam LM, Reznikoff WS, Rayment I; J Biol Chem 1999;274:11904-11913. PMID:10207011

2: DNA sequences at the ends of transposon Tn5 required for transposition. Johnson RC, Reznikoff WS; Nature 1983;304:280-282. PMID:6306482