A network of MGEs and CRISPR-Cas defense systems mediated through PAMs. Only selected MGEs and CRISPR types are shown, for demonstration purposes. Blue rectangles represent CRISPRs; red rectangles represent MGE contigs. The WebLogo of PAM for the protospacers is plotted on the edges between the corresponding nodes of the MGE and CRISPR. The logos include 10 positions: -4 to 0 for the protospacers and 1 to 5 for the adjoining regions containing the PAM. PAM, protospacer-adjacent motifs.
Zhang et al. Genome Biology 2013 14:R40 doi:10.1186/gb-2013-14-4-r40