Bacterial virus anti-defence systems · sequence & structure resource

Encyclopaedia of Bacterial Virus Anti-Defence Systems


Protein: Anti-TerI1

Download all data for this protein (.zip)

Overview

Mode of Action (MoA) prophage encoded anti-defence protein counteracting self-encoded defence system, TerI. TerI targets the terminase complex of invading phages, and anti-TerI1 and anti-Terl2 counteract Terl through direct interaction during prophage induction to allow virion production.
Evidence Anti-TerI1 (encoded by LMRG_01518) was identified as a self-immunity factor that neutralizes the anti-phage defense protein TerI. Its function was revealed through a suppressor screen using terI-expressing bacteria repeatedly infected with phage ϕ10403S, which selected for a phage mutant with enhanced early gene expression and resistance to TerI inhibition. Overexpression of LMRG_01518 in terI-expressing cells restored virion production to wild-type levels, confirming its counter-defensive role. Deletion of LMRG_01518 (ECO_0001038) impaired virion production upon prophage induction, resulting in capsids devoid of DNA, a phenotype rescued by inactivating terI expression. This demonstrates that Anti-TerI1 counteracts TerI activity in vivo. When overexpressed alone, Anti-TerI1 also rescued virion production during exogenous phage infection, confirming its ability to neutralize TerI's anti-phage activity.
MoA Category binds and inhibits host defence system
Subtype(s) of the defence system(s) inhibited by the protein Defence Subtype Prophage ϕ10403S TerI defence system (active in Listeria monocytogenes)
Relevant publication(s) DOI 10.1101/2025.02.27.640495
Other components of the anti-defence system Multicomponent System anti_rerI2
Known structure in PDB PDB ID -
Genome(s) encoding the protein Protein Source Prophage ϕ10403S
Defence system(s) inhibited by the protein Defences TerI

3D structure

AlphaFold 3 model.

Download structure file

Feature viewer - predicted secondary structure

Download features JSON file

Pfam annotations

No Pfam domains found

Sequence Viewer

Amino acid position: -

MNNIKQAIIKLETILENGNAIESGSFVKYSVIKNILNLLEKDQELKIIEMEVELNGVEDSIENAALLEKRLSEAKSLVEDLASTINSLEIKVK