transposases

Transposases are enzymes that catalyze the movement of transposable elements, or transposons, within genomes. They recognize specific sequences at the ends of the transposon, excise the element from its original location, and insert it into a new genomic site. This movement can occur via conservative (cut-and-paste) or replicative (copy-and-paste) mechanisms, producing either precise excisions or characteristic footprints at donor sites.

Most DNA transposases are encoded by autonomous transposons and act as part of a transposition complex, or transpososome, that brings the element ends together for cleavage and strand transfer. Many belong to the DDE family of enzymes, which coordinate metal ions to catalyze DNA strand scission and joining; others use alternative catalytic motifs. Transposition typically requires terminal inverted repeats at the transposon's ends and, in some cases, a target site duplication upon insertion.

Transposases are widespread across bacteria, archaea, and eukaryotes, and their activity contributes to genome rearrangements, gene disruption, and the spread of antibiotic resistance genes among bacteria. In multicellular organisms, transposases have been harnessed as molecular tools for genome manipulation. Well-known examples include the Sleeping Beauty and piggyBac transposase systems used in vertebrate genetics, as well as P element transposase in Drosophila and various Tc1/mariner family elements.

Because their mobility can alter gene expression and genome structure, transposases are studied for evolution, genetic stability, and biotechnology applications. Research continues to characterize their regulation, host interactions, and potential therapeutic uses.