The bacterial transposon Tn7 facilitates horizontal transfer by directing transposition into actively replicating DNA with the element-encoded protein TnsE. Structural analysis of the C-terminal domain of TnsE identified a central V-shaped loop that toggles between two distinct conformations. It is suggested that a conformational change within the C-terminal domain of TnsE underlies target site selection by regulating stable engagement of the target DNA while providing a signal for activating transposition [1].

1: Conformational toggling controls target site choice for the heteromeric transposase element Tn7. Shi Q, Straus MR, Caron JJ, Wang H, Chung YS, Guarne A, Peters JE; Nucleic Acids Res. 2015;43:10734-10745. PMID:26384427