Schematic representations of IS1006, IS1008, the hybrid IS1006/1008, and IS26::catA1. (A) Nucleotide sequences belonging to IS1006 and IS1008 are shaded in orange and blue, respectively. The crossover between the two sequences in IS1006/1008 is marked by a vertical line, indicating the first base belonging exclusively to IS1008. The extent and orientation of the transposase open reading frame are indicated by a black arrow. Amino acids that differ between the transposases are marked by red and black letters. The H-HTH putative DNA binding domain and the DDE catalytic domain are marked at the top. The positions of the conserved DDE catalytic triad are marked by bold letters. In IS1006/1008, the nucleotide identity between IS1006 and IS1008 is indicated in the two segments. Drawn to scale from GenBank accession numbers CP012956, CP041590, and KU744946 for IS1006, IS1006/1008, and IS1008, respectively. (B) The synthetic IS26::catA1 construct is shown with IS26 in green and the catA1 gene fragment in orange. The extent and orientation of the tnp26 and catA1 genes are indicated by a black arrow. The position of the inserted catA1 fragment in IS26 is marked.