Characterization of IS elements of Lxc dataset. Each characterized IS element is represented by a rectangle, with IRs indicated by gray triangles. Black vertical bars indicate start and stop codons of the deduced transposases, and their transcriptional orientation is indicated by arrows. Crossed arrows represent truncated ORFs. Regions with slippery codons for frameshift are represented by X and the corresponding nucleotides are depicted in capital letters, with other nucleotides in lowercase letters. Amino acid sequences are shown beneath boxed codons. Vertical bars with asterisks represent premature stop codons. Inverted black triangles indicate the location of an IS1237 insertion within other IS elements, and the arrows above indicate the orientation of transcription of its transposase. In (b) we presented the nucleotides and deduced amino acid sequences immediately after the purine rich region that may promote either: (i) independent translation of istA and istB, or (ii) translation of istAB, depending on ribosomal slippage. In (c) copies of IS1237 were found inserted in both orientations (i and ii) when considering transcription of its transposase within ISLxc2. (e) in (i) indicates independent translation of orfA and (ii) shows translation of the same nucleotides after a +1 frameshift (translation of orfAB).