Figure 1.

S. thermophilus CRISPR4-Cas crRNA and Cascade complex. (A) Schematic representation of the CRISPR4-Cas locus containing eight cas genes and twelve repeat-spacer units (conserved 28-bp palindromic repeats 5′-GTTTTTCCCGCACACGCGGGGGTGATCC-3′ are separated from each other by 33-bp spacers of variable sequence). St-Cascade genes homologous to the E. coli Cascade are underlined. Genes names according to Brouns et al (2008) and Makarova et al (2011) are indicated, respectively, above and below corresponding genes. (B) Coomassie blue-stained SDS-polyacrylamide gel of St-Cascade complex proteins isolated using the CasC-His₆ protein as bait. (C) IP RP HPLC analysis of mature crRNA. (D) LC ESI-MS analysis of purified S. thermophilus crRNA. Inset shows an enhanced view of the 22-charge state. (E) Architecture of crRNA co-purifying with the St-Cascade protein complex.

Source data for this figure is available on the online supplementary information page.

Source Data for Figure 1 ^{(177.9KB, pdf)}