This domain occurs at the C-terminus of transposases including E. coli tnpA. TnpA encodes a transposase and an inhibitor protein, the inhibitor only differs from the transposase by the absence of the N-terminal 55 amino acids, which includes most of this domain. This domain consists of alpha helices and turns, and functions as a DNA-binding domain.
Jiyao W et al.(2023). "The conserved domain database in 2023.",