<p>Autonomous mobile genetic elements such as transposon or insertion sequences (IS) encode an enzyme, called transposase, required for excising and inserting the mobile element. On the basis of sequence similarities, transposases can be grouped into various families. One of these families has been shown [<cite idref="PUB00002208"/>, <cite idref="PUB00003122"/>] to consist of proteins of 340 to 380 amino acids.</p><p>More information about these proteins can be found at Protein of the Month: Transposase [<cite idref="PUB00034633"/>].</p>