Crl Binds to Domain 2 of S and Confers a Competitive Advantage on a Natural rpoS Mutant of Salmonella enterica Serovar Typhi - Institut Pasteur Access content directly
Journal Articles Journal of Bacteriology Year : 2010

Crl Binds to Domain 2 of S and Confers a Competitive Advantage on a Natural rpoS Mutant of Salmonella enterica Serovar Typhi

Abstract

The RpoS sigma factor (σ(S)) is the master regulator of the bacterial response to a variety of stresses. Mutants in rpoS arise in bacterial populations in the absence of stress, probably as a consequence of a subtle balance between self-preservation and nutritional competence. We characterized here one natural rpoS mutant of Salmonella enterica serovar Typhi (Ty19). We show that the rpoS allele of Ty19 (rpoS(Ty19)) led to the synthesis of a σ(S)(Ty19) protein carrying a single glycine-to-valine substitution at position 282 in σ(S) domain 4, which was much more dependent than the wild-type σ(S) protein on activation by Crl, a chaperone-like protein that increases the affinity of σ(S) for the RNA polymerase core enzyme (E). We used the bacterial adenylate cyclase two-hybrid system to demonstrate that Crl bound to residues 72 to 167 of σ(S) domain 2 and that G282V substitution did not directly affect Crl binding. However, this substitution drastically reduced the ability of σ(S)(Ty19) to bind E in a surface plasmon resonance assay, a defect partially rescued by Crl. The modeled structure of the Eσ(S) holoenzyme suggested that substitution G282V could directly disrupt a favorable interaction between σ(S) and E. The rpoS(Ty19) allele conferred a competitive fitness when the bacterial population was wild type for crl but was outcompeted in Δcrl populations. Thus, these results indicate that the competitive advantage of the rpoS(Ty19) mutant is dependent on Crl and suggest that crl plays a role in the appearance of rpoS mutants in bacterial populations.

Domains

Bacteriology
Fichier principal
Vignette du fichier
PMID 20935100.pdf (2.74 Mo) Télécharger le fichier
Origin Files produced by the author(s)

Dates and versions

pasteur-01414252 , version 1 (27-12-2016)

Licence

Identifiers

Cite

Véronique Monteil, Annie Kolb, Claudine Mayer, Sylviane Hoos, Patrick England, et al.. Crl Binds to Domain 2 of S and Confers a Competitive Advantage on a Natural rpoS Mutant of Salmonella enterica Serovar Typhi. Journal of Bacteriology, 2010, 192 (24), pp.6401 - 6410. ⟨10.1128/JB.00801-10⟩. ⟨pasteur-01414252⟩
273 View
140 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More