Figure 1.

Multiple sequence alignment of the topoisomerase IB sequences extracted from C. symbiosum, C. elegans, X. laevis, C. griseus, M. musculus, R. norvegicus, C. aethiops, H. sapiens, A. thaliana and C. acuminata, respectively. The alignment of the residues in proximity of the catalytic pentad (Arg488, Lys532, Arg590, His632, Tyr723 for the human isoform) and along the full linker domain is reported. Residues conserved in all sequences are highlighted by a grey column and evidenced by an asterisk. The residues belonging to the linker domain are underlined. The mutated residue Lys681 is evidenced by a black triangle.