Comparison of the sequence motifs of ISCR20 and those of the IS91 family transposases. The sequences (with their GenBank accession numbers shown in parentheses) shown are as follows: ISCR1 (FJ187822), ISCR2 (AY055428), ISCR3 group, including ISCR3, ISCR4, ISCR6, ISCR14, and ISCR16 (FJ183463), ISCR7 (AJ250371), ISCR8 (AF028594), ISCR15 (AM998375), and ISCR19 (EU503121). The five motifs found within IS91 group elements are indicated. The amino acid residues conserved in all IS91 group elements are shown boxed. Gaps introduced to maximize alignment are indicated by dashes.