Anti-CRISPR regulator Aca2 binds both DNA and RNA to control phage anti-CRISPR production (Nature)

The helix-turn-helix regulator Aca2 represses phage anti-CRISPR synthesis transcriptionally by binding DNA and also inhibits translation of the mRNAs by binding conserved RNA stem-loops and blocking ribosome access; a cryo-EM structure of the Aca2-RNA complex shows how it discriminates RNA from DNA sites. The authors say these combined modes let phages inhibit CRISPR-Cas despite rapid DNA replication without toxic anti-CRISPR overexpression.