The integration preference of Sleeping Beauty at non-TA site is related to the transposon end sequences

Abstract Background: Sleeping Beauty (SB) transposon had been thought to strictly integrate into TA dinucleotides. Recently, we found that SB also integrates into non-TA sites at a lower frequency. Here we performed further study on the non-TA integration of SB. Results: 1) SB can integrate into non-TA sites in HEK293T cells as well as in mouse cell lines. 2) Both the hyperactive transposase SB100X and the traditional SB11 catalyze integrations at non-TA sites. 3) The consensus sequence of the non-TA target sites only occur at the opposite side of the sequenced junction between transposon end and the genomic sequences, indicating that the integrations at non-TA sites are mainly aberrant integrations. 4) The consensus sequence of the non-TA target sites is corresponding to the transposon end sequence. When the transposon end sequence is mutated, the consensus sequences changed too. Conclusion: The interaction between the SB transposon end and genomic DNA may be involved in the target site selection of the SB integrations at non-TA sites.