The Tn7 transposase is composed of proteins TnsA and TnsB. DNA breakage at the 5' end of the transposon is carried out by TnsA, and breakage and joining at the 3' end is carried out by TnsB. The C terminal domain of TnsA binds DNA.

1: Unexpected structural diversity in DNA recombination: the restriction endonuclease connection. Hickman AB, Li Y, Mathew SV, May EW, Craig NL, Dyda F; Mol Cell. 2000;5:1025-1034. PMID:10911996