The invention provides a retrotransposase, which comprises a target
DNA binding structural domain containing a
zinc finger binding motif, a
reverse transcriptase structural domain and an
endonuclease structural domain, and can be used for reversely transcribing
RNA (Ribonucleic Acid) into
DNA. The
amino acid sequence of the retrotransposase is shown as any one of SEQ ID No.1 to 6 or SEQ ID No.32 to 43 or SEQ ID No.68 to 71 or has at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% and 99% identity with the
amino acid sequence of any one of SEQ ID No.1 to 6 or SEQ ID No.32 to 43 or SEQ ID No.68 to 71. The invention also relates to a
system for modifying
DNA. The
system comprises the retrotransposase provided by the invention or a
nucleic acid encoding the retrotransposase provided by the invention; and a donor
RNA or a
nucleic acid encoding the donor
RNA, the donor RNA comprising: a sequence that binds to the retrotransposase and a
heterologous sequence.