3.A.1.5.41
Oligopeptide transporter, OppABCDF/MppA/YgiS.  MppA is a murein peptide receptor, and YgiS is a bile acid (e.g., cholate, deoxycholate) receptor that may use the Opp system for uptake.  YgiS mRNA is degraded by the toxin, MgsR, which is regulated by the antitoxin, MgsA, and this loss of the mRNA protects the cell against bile acid stress (Kwan et al. 2015). oppA translation is activated by MicF through a mechanism of action involving facilitated access to a translation-enhancing region in oppA 5'UTR.  MicF activation of oppA translation depends on cross-regulation by negative trans-acting effectors, the GcvB sRNA and the RNA chaperone protein Hfq (Carrier et al. 2023).