Figure 2.

Sequence alignment and structural superposition identifies H187 in the Sleeping Beauty transposase as a potential homologue of R186 in the Mos1 transposase responsible for interactions with target DNA. (A) Amino acid sequence alignment of segments of the SB and Mos1 transposases. The alignment was generated by CLUSTALW and then used to highlight secondary structures of the Mos1 transposase (based on PDB ID: 4U7B) with ESPript 3.0 (100). Accordingly, the numbering of alpha helices and beta strands corresponds to Mos1. The second D residue of the catalytic DDE/D triad is marked by an asterisk. H187 in SB (arrow) aligns with R186 in Mos1. (B) An overlay of the SB TCC model (orange) with the Mos1 STC [gray, PDB ID: 5HOO (28)] shows that H187 in SB aligns with R186 in Mos1. The target DNA is depicted in dark gray.