This invention relates to a system for introducing nucleic acid into the DNA of a cell. The system includes the use of a member of the SB family of transposases (SB) or nucleic acid encoding the transposase and a nucleic acid fragment that includes a nucleic acid sequence with flanking inverted repeats. The transposase recognizes at least a portion of an inverted repeats and incorporates the nucleic acid sequence into the DNA. Methods for use of this system are discussed.