Figure 3

Diagram of the CRISPR-Cas locus of B. pseudocatenulatum IPLA 36007. Panel A: The type I CRISPR–Cas systems seem to target DNA. Orthologous genes are color coded following protein family relationships as suggested by Makarova et al. [20]. Cas3 is a large protein with separate helicase and DNase activities. Either Cas5 or Cas7 possess RNase activity. CRISP repeats and spacers are indicated by rectangles and rhombs. In grey, bounding CDS not related to the CRISPR-Cas system. Panel B: Twenty two identical 33 base pair (bp) repeats (except for repeat 21, which harbors a single bp change) are separated by unrelated 32 to 37 bp spacers. Pale blue background boxes indicate functionally coupled genes sharing conserved relative positions in the genome of at least four other species.