Figure 9.

Regulation of Rtc RNA repair system expression and function

Under conditions that activate of the Rtc RNA repair system that helps maintain translation, RtcA and RtcB interact with the RtcR CARF domain together with an unknown ligand, leading to derepression of the RtcR AAA + domain by the RtcR CARF domain. We propose that the complex has dual functionality: transcriptional activation of rtcBA by RtcR and RNA repair by RtcA and RtcB. The RtcR CARF domain likely does not use cOAs as activating ligands (this work), rather it binds particular linear RNA sequences with a 2’-3’ cyclic P end (this work and Hughes et al., 2020¹⁸).