Figure 3.

Alignment of the predicted active site motifs of BspRI and the putative REases (Table 2) sharing the highest amino acid sequence similarity with BspRI. Numbers at the beginning of the sequences designate the position of the first amino acid shown. The numbers of residues between the shown blocks of sequences are given in parentheses. Predicted α-helices and β-strands (41), are indicated at the top. The convention of numbering, with Roman numerals, the secondary structural elements of the PD-(D/E)XK conserved fold is adopted from (48). Conserved residues of the putative PD-(D/E)XK nuclease fold (47,48) are highlighted with colored background: red, acidic; grey, lysine; yellow, uncharged.