Dual regulation of HEPN RNase in fused MNT-HEPN toxin-antitoxin systems via protein OligoAMPylation and oligomerization - PubMed
6 hours ago
- #oligoAMPylation
- #HEPN RNase
- #toxin-antitoxin systems
- HEPN domain-containing proteins have a conserved RNase motif and are found in both prokaryotes and eukaryotes.
- Prokaryotic HEPN domain toxins often pair with MNT domain antitoxins to form type VII HepT/MntA toxin-antitoxin (TA) systems.
- Fused MNT-HEPN proteins (FhepTA) in Shewanella genus resemble HepT/MntA TA systems and are carried by mobile genetic elements.
- MntA antitoxin oligoAMPylates HepT toxin to block its toxicity when encoded as separate genes.
- FhepTA toxicity is regulated by oligoAMPylation and a redox switch involving two unique cysteines in its HEPN domain.
- The N-terminal MNT domain in FhepTA inhibits toxicity by preventing dimerization of the C-terminal HEPN domain.
- Fused MNT-HEPN architecture represents a new family of TA modules regulated by ATP-dependent oligoAMPylation and redox-state-dependent oligomerization.