IS Families/ISAzo13 family
This family, represented by 37 members in ISfinder emerged from the ISNCY orphan group. It is based on both Tpase and IR sequence similarities (Fig. ISAzo13.1). Insertion generates a 3bp AT-rich DR and the ends have a consensus GGa/g. Their Tpases are highly conserved with a probable DDE motif and an HTH motif at the N-terminus which could function as a DNA binding domain. Two members encode two orfs with a possible PRF (programmed transcriptional frameshifting) motif of 8 or 9 A while the other members encode a unique orf which includes a triple lysine at the equivalent position (Gourbeyre, unpublished).