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). 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9 A while the other members encode a unique orf which includes a triple lysine at the equivalent position (Gourbeyre, unpublished)[1].
Fig. ISAzo13.General ISAzo13 characteristics, average length and common ends. Top: Distribution of IS length (base pairs) of ISAzo13 family members. The number of examples used in the sample is shown above each column. Bottom: Left (IRL) and right IRR inverted terminal repeats are shown in WebLogo format.
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