The Sleeping Beauty (SB) transposase is the recombinase that drives the Sleeping Beauty transposon system.  SB transposase belongs to the DD[E/D] family of transposases, which in turn belong to a large superfamily of polynucleotidyl transferases that includes RNase H, RuvC Holliday resolvase, RAG proteins, and retroviral integrases. The SB system is used primarily in vertebrate animals for gene transfer, including gene therapy, and gene discovery.  The engineered SB100X is an enzyme that directs the high levels of transposon integration.