Figure 3.

Highlighting the advantage of independent clustering approaches. (A) CRISPRs in the largest sequence family, F1, are mostly unstructured; however, for 50 CRISPRs also a conserved structure motif, M10, was identified. This indicates that subsets of conserved families can be structured. F1 contains the conserved 5′ tag, marked with the magenta box. (B) Structure motif M28 shows no sequence conservation, but a conserved structure (base pairs are highlighted in yellow). The many compensatory base pairs are marked in the alignment with squares. This structure has been verified via mutational analyses in (20). Potential cleavage sites are indicated as observed in the literature (13,17–21,23–25,33–36).