Extended Data Fig. 9: Effects of type III-A CRISPR–Cas immunity on self and non-self DNA.
From: Type III-A CRISPR immunity promotes mutagenesis of staphylococci
During type III-A CRISPR–Cas immunity the ssDNase activity of Cas10 (HD domain) is activated by the recognition of a target transcript produced by the invading phage or plasmid. On the one hand, destruction of foreign DNA by this activity provides immunity and restricts evolution through horizontal gene transfer. On the other hand, non-specific ssDNA degradation can also damage the host chromosome, leading to the induction of the SOS response and error-prone repair, and facilitating evolution through mutagenesis.
