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Identification of conserved amino acid residues of the Salmonella sigmaS chaperone Crl involved in Crl-sigmaS interactions.
J Bacteriol. 2010 Feb; 192(4):1075-87.JB

Abstract

Proteins that bind sigma factors typically attenuate the function of the sigma factor by restricting its access to the RNA polymerase (RNAP) core enzyme. An exception to this general rule is the Crl protein that binds the stationary-phase sigma factor sigma(S) (RpoS) and enhances its affinity for the RNAP core enzyme, thereby increasing expression of sigma(S)-dependent genes. Analyses of sequenced bacterial genomes revealed that crl is less widespread and less conserved at the sequence level than rpoS. Seventeen residues are conserved in all members of the Crl family. Site-directed mutagenesis of the crl gene from Salmonella enterica serovar Typhimurium and complementation of a Deltacrl mutant of Salmonella indicated that substitution of the conserved residues Y22, F53, W56, and W82 decreased Crl activity. This conclusion was further confirmed by promoter binding and abortive transcription assays. We also used a bacterial two-hybrid system (BACTH) to show that the four substitutions in Crl abolish Crl-sigma(S) interaction and that residues 1 to 71 in sigma(S) are dispensable for Crl binding. In Escherichia coli, it has been reported that Crl also interacts with the ferric uptake regulator Fur and that Fur represses crl transcription. However, the Salmonella Crl and Fur proteins did not interact in the BACTH system. In addition, a fur mutation did not have any significant effect on the expression level of Crl in Salmonella. These results suggest that the relationship between Crl and Fur is different in Salmonella and E. coli.

Authors+Show Affiliations

Institut Pasteur, Unité de Génétique Moléculaire, CNRS URA2172, Paris, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

20008066

Citation

Monteil, Véronique, et al. "Identification of Conserved Amino Acid Residues of the Salmonella sigmaS Chaperone Crl Involved in Crl-sigmaS Interactions." Journal of Bacteriology, vol. 192, no. 4, 2010, pp. 1075-87.
Monteil V, Kolb A, D'Alayer J, et al. Identification of conserved amino acid residues of the Salmonella sigmaS chaperone Crl involved in Crl-sigmaS interactions. J Bacteriol. 2010;192(4):1075-87.
Monteil, V., Kolb, A., D'Alayer, J., Beguin, P., & Norel, F. (2010). Identification of conserved amino acid residues of the Salmonella sigmaS chaperone Crl involved in Crl-sigmaS interactions. Journal of Bacteriology, 192(4), 1075-87. https://doi.org/10.1128/JB.01197-09
Monteil V, et al. Identification of Conserved Amino Acid Residues of the Salmonella sigmaS Chaperone Crl Involved in Crl-sigmaS Interactions. J Bacteriol. 2010;192(4):1075-87. PubMed PMID: 20008066.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Identification of conserved amino acid residues of the Salmonella sigmaS chaperone Crl involved in Crl-sigmaS interactions. AU - Monteil,Véronique, AU - Kolb,Annie, AU - D'Alayer,Jacques, AU - Beguin,Pierre, AU - Norel,Françoise, Y1 - 2009/12/11/ PY - 2009/12/17/entrez PY - 2009/12/17/pubmed PY - 2010/2/17/medline SP - 1075 EP - 87 JF - Journal of bacteriology JO - J Bacteriol VL - 192 IS - 4 N2 - Proteins that bind sigma factors typically attenuate the function of the sigma factor by restricting its access to the RNA polymerase (RNAP) core enzyme. An exception to this general rule is the Crl protein that binds the stationary-phase sigma factor sigma(S) (RpoS) and enhances its affinity for the RNAP core enzyme, thereby increasing expression of sigma(S)-dependent genes. Analyses of sequenced bacterial genomes revealed that crl is less widespread and less conserved at the sequence level than rpoS. Seventeen residues are conserved in all members of the Crl family. Site-directed mutagenesis of the crl gene from Salmonella enterica serovar Typhimurium and complementation of a Deltacrl mutant of Salmonella indicated that substitution of the conserved residues Y22, F53, W56, and W82 decreased Crl activity. This conclusion was further confirmed by promoter binding and abortive transcription assays. We also used a bacterial two-hybrid system (BACTH) to show that the four substitutions in Crl abolish Crl-sigma(S) interaction and that residues 1 to 71 in sigma(S) are dispensable for Crl binding. In Escherichia coli, it has been reported that Crl also interacts with the ferric uptake regulator Fur and that Fur represses crl transcription. However, the Salmonella Crl and Fur proteins did not interact in the BACTH system. In addition, a fur mutation did not have any significant effect on the expression level of Crl in Salmonella. These results suggest that the relationship between Crl and Fur is different in Salmonella and E. coli. SN - 1098-5530 UR - https://www.unboundmedicine.com/medline/citation/20008066/Identification_of_conserved_amino_acid_residues_of_the_Salmonella_sigmaS_chaperone_Crl_involved_in_Crl_sigmaS_interactions_ L2 - https://journals.asm.org/doi/10.1128/JB.01197-09?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -