This family of proteins are related to Pfam:PF00665 and are probably endonucleases of the DDE superfamily. Transposase proteins are necessary for efficient DNA transposition. This domain is a member of the DDE superfamily, which contain 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. Interestingly this family also includes the CENP-B protein. This domain in that protein appears to have lost the metal binding residues and is unlikely to have endonuclease activity. Centromere Protein B (CENP-B) is a DNA-binding protein localised to the centromere.