A method for the generation of DNA fragmentation library based on a transposition reaction in the presence of a transposon end with an engineered cleaveage site providing facilitated downstream handling of the produced DNA fragments, e.g., in the generation of sequencing templates. Transposon nucleic acids comprising a transposon end sequence and an engineered cleaveage site located in the sequence, e.g., in Mu transposon end sequence, are disclosed.