RT_G2_intron: Reverse transcriptases (RTs) with group II intron origin. RT transcribes DNA using RNA as template. Proteins in this subfamily are found in bacterial and mitochondrial group II introns. Their most probable ancestor was a retrotransposable element with both gag-like and pol-like genes. This subfamily of proteins appears to have captured the RT sequences from transposable elements, which lack long terminal repeats (LTRs).