摘要：SummaryCRISPR-associated Rossmann fold (CARF) domain signaling underpins modulation of CRISPR-Cas nucleases; however, the RtcR CARF domain controls expression of two conserved RNA repair enzymes, cyclase RtcA and ligase RtcB. Here, we demonstrate that RtcAB are required for RtcR-dependent transcription activation and directly bind to RtcR CARF. RtcAB catalytic activity is not required for complex formation with CARF, but is essential yet not sufficient for RtcRAB-dependent transcription activation, implying the need for an additional RNA repair-dependent activating signal. This signal differs from oligoadenylates, a known ligand of CARF domains, and instead appears to originate from the translation apparatus: RtcB repairs a tmRNA that rescues stalled ribosomes and increases translation elongation speed. Taken together, our data provide evidence for an expanded range for CARF domain signaling, including the first evidence of its control viain transprotein-protein interactions, and a feed-forward mechanism to regulate RNA repair required for a functioning translation apparatus.Graphical abstractDisplay OmittedHighlights•RtcR physically interacts with RtcB and RtcA via its regulatory CARF domain•RtcR-RtcBA interactions positively controlrtcBAexpression•The transfer-messenger RNAssrAis a target ofrtcinducing stress•RtcB impacts the speed of translation elongationMolecular biology; Molecular mechanism of gene regulation; Cell biology
