Has reverse transcriptase activity required for target-primed reverse transcription of the LINE-1 element mRNA, a crucial step in LINE-1 retrotransposition (, ). Also has endonuclease activity that allows the introduction of nicks in the chromosomal target DNA ( ). Cleaves DNA in AT-rich regions between a 5' stretch of purines and a 3' stretch of pyrimidines, corresponding to sites of LINE-1 integration in the genome . Conformational properties of the target DNA sequence rather than specific nucleotides are key determinants of the ORF2p capacity for sequence-specific DNA recognition (, ). Unlike related endonucleases, does not bend the DNA helix but causes compression near the cleavage site .