PDBsum entry 6f8h

Antitoxin

PDB id: 6f8h

Contents

Protein chains

96 a.a.

Waters ×241

PDB id:

6f8h

Name:

Antitoxin

Title:

Antitoxin graa

Structure:

Xre family transcriptional regulator. Chain: a, b, c, d. Engineered: yes

Source:

Pseudomonas putida. Arthrobacter siderocapsulatus. Organism_taxid: 303. Gene: ayo08_18510. Expressed in: escherichia coli bl21. Expression_system_taxid: 511693

Resolution:

2.00Å R-factor: 0.192 R-free: 0.226

Authors:

A.Talavera,R.Loris

Key ref:

A.Talavera et al. (2019). A dual role in regulation and toxicity for the disordered N-terminus of the toxin GraT. Nat Commun, 10, 972. PubMed id: 30814507 DOI: 10.1038/s41467-019-08865-z

Date:

13-Dec-17 Release date: 30-Jan-19

Protein chains

A0A179R2V1  () -

DOI no: 10.1038/s41467-019-08865-z

Nat Commun 10:972 (2019)

PubMed id: 30814507

A dual role in regulation and toxicity for the disordered N-terminus of the toxin GraT.

A.Talavera, H.Tamman, A.Ainelo, A.Konijnenberg, S.Hadži, F.Sobott, A.Garcia-Pino, R.Hõrak, R.Loris.

ABSTRACT

Bacterial toxin-antitoxin (TA) modules are tightly regulated to maintain growth in favorable conditions or growth arrest during stress. A typical regulatory strategy involves the antitoxin binding and repressing its own promoter while the toxin often acts as a co-repressor. Here we show that Pseudomonas putida graTA-encoded antitoxin GraA and toxin GraT differ from other TA proteins in the sense that not the antitoxin but the toxin possesses a flexible region. GraA auto-represses the graTA promoter: two GraA dimers bind cooperatively at opposite sides of the operator sequence. Contrary to other TA modules, GraT is a de-repressor of the graTA promoter as its N-terminal disordered segment prevents the binding of the GraT₂A₂ complex to the operator. Removal of this region restores operator binding and abrogates Gr aT toxicity. GraTA represents a TA module where a flexible region in the toxin rather than in the antitoxin controls operon expression and toxin activity.