Bacterial virus anti-defence systems · sequence & structure resource

Encyclopaedia of Bacterial Virus Anti-Defence Systems


Protein: RexB

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Overview

Mode of Action (MoA) stabilises the antitoxin MazE by affecting the ClpP proteases responsible for its degradation.
Evidence In P1 phd‑doc tests, cells expressing wild-type rexB survived plasmid loss at high temperature (ECO_0000017), whereas rexB mutants (nonsense or deletion) did not. Induction of ppGpp—or amino acid starvation via serine hydroxamate—to activate mazEF leads to ~90% killing; but rexB, either from plasmid or a λ lysogen, restores survival up to ~60–100% depending on the setup. Pulse-chase experiments demonstrated that λRexB extends the half-life of the antitoxins Phd (from P1) and MazE (from E. coli), both substrates of ClpP proteases (ClpPX and ClpPA, respectively)
MoA Category uncategorised
Subtype(s) of the defence system(s) inhibited by the protein Defence Subtype Escherichia coli type II TA system MazEF
Relevant publication(s) DOI 10.1073/pnas.95.26.15481
Other components of the anti-defence system Multicomponent System -
Known structure in PDB PDB ID -
Genome(s) encoding the protein Protein Source Enterobacteria phage lambda
Defence system(s) inhibited by the protein Defences TA

3D structure

AlphaFold 3 model.

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Feature viewer - predicted secondary structure

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Pfam annotations

Pfam Name Pfam Acc Pfam Length Colour HMM Start HMM End Ali Start Ali End Env Start Env End Evalue
RexB PF15968 139 1 139 6 144 6 144 9.2e-94

Sequence Viewer

Amino acid position: -

MRNRIMPGVYIVIIPYVIVSICYLLFRHYIPGVSFSAHRDGLGATLSSYAGTMIAILIAALTFLIGSRTRRLAKIREYGYMTSVVIVYALSFVELGALFFCGLLLLSSISGYMIPTIAIGIASASFIHICILVFQLYNLTREQE