Extended Data Fig. 1: AcrIF23 and AcrIF24 inhibit in vitro DNA cleavage by Csy and Cas2/3.
From: Structural basis of AcrIF24 as an anti-CRISPR protein and transcriptional suppressor
(a) Cartoon diagram of the acrIF23-acrIF24 operon found in a P. aeruginosa prophage. No aca gene downstream of the acrIF23–24 locus was found. In comparison, the aca9 gene was found downstream of acrIF23 in a D. carbinolicus prophage. Adapted from6. (b) AcrIF23 and AcrIF24 inhibits substrate DNA cleavage by the type I-F CRISPR-Cas system in the in vitro DNA cleavage assay. (c) Quantitative result of the experiment in (b). Error bars represent SD; n = 3. Two-sided t test was performed (*P < 0.05). (d) EMSA results reveal that AcrIF24 inhibits substrate DNA binding to Csy whereas AcrIF23 does not. Note: Csy–AcrIF24 is capable of binding DNA independent of PAM and spacer sequences, resulting in a high molecular weight shift. * indicates a faint band where two copies of Csy bound to DNA, similar to previous report14 (doi.org/10.1093/nar/gkab092). (e) Quantitative result of the experiment in (d). Error bars represent SD; n = 3. Two-sided t test was performed (*P < 0.05). (f) EMSA results reveal that Cas2/3 recruitment by Csy is abolished by AcrIF24 but not by AcrIF23.
