Do non-long terminal repeat retrotransposons have nuclease activity?

Abstract

A high level of homology has been found between regions of the non-long terminal repeat (LTR) retrotransposons (non-site-specific) and the AP endonuclease protein family.The presence of the exo lII active residues and the conserved amino acids involved in DNase I acid-base catalysis, in similar regions of the non-site-specific non-LTR retrotransposons, provides an even stronger argument in favor of the potential nuclease activity of these elements. Within this framework, the potential endonuclease activity could be responsible for generating the 3'-OH sites necessary as primers for its reverse transcription (first step in the integration mechanism). This would render the existence of nicks in the DNA necessary for the integration of the non-LTR elements.