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Salmonella enterica response regulator SsrB relieves H-NS silencing by displacing H-NS bound in polymerization mode and directly activates transcription.
J Biol Chem. 2011 Jan 21; 286(3):1895-902.JB

Abstract

The response regulator SsrB activates expression of genes encoded within and outside of a pathogenicity island (SPI-2), which is required for systemic infection of Salmonella. SsrB binds upstream of the sifA, sifB, and sseJ effector genes and directly regulates transcription. SsrB also relieves gene silencing by the nucleoid protein H-NS. Single molecule experiments with magnetic tweezers demonstrated that SsrB displaces H-NS from DNA only when it is bound in a polymerization (stiffening) mode and not when H-NS is bound to DNA in the bridging mode. Thus, in contrast to previous views, the polymerization binding mode of H-NS is the relevant form for counter-silencing by SsrB. Our results reveal that response regulators can directly activate transcription and also relieve H-NS silencing. This study adds to the repertoire of mechanisms by which NarL/FixJ subfamily members regulate transcription. Because SsrB-dependent promoters are diversely organized, additional mechanisms of transcriptional activation at other loci are likely.

Authors+Show Affiliations

Department of Microbiology and Immunology, University of Illinois, Chicago, Illinois 60612, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

21059643

Citation

Walthers, Don, et al. "Salmonella Enterica Response Regulator SsrB Relieves H-NS Silencing By Displacing H-NS Bound in Polymerization Mode and Directly Activates Transcription." The Journal of Biological Chemistry, vol. 286, no. 3, 2011, pp. 1895-902.
Walthers D, Li Y, Liu Y, et al. Salmonella enterica response regulator SsrB relieves H-NS silencing by displacing H-NS bound in polymerization mode and directly activates transcription. J Biol Chem. 2011;286(3):1895-902.
Walthers, D., Li, Y., Liu, Y., Anand, G., Yan, J., & Kenney, L. J. (2011). Salmonella enterica response regulator SsrB relieves H-NS silencing by displacing H-NS bound in polymerization mode and directly activates transcription. The Journal of Biological Chemistry, 286(3), 1895-902. https://doi.org/10.1074/jbc.M110.164962
Walthers D, et al. Salmonella Enterica Response Regulator SsrB Relieves H-NS Silencing By Displacing H-NS Bound in Polymerization Mode and Directly Activates Transcription. J Biol Chem. 2011 Jan 21;286(3):1895-902. PubMed PMID: 21059643.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Salmonella enterica response regulator SsrB relieves H-NS silencing by displacing H-NS bound in polymerization mode and directly activates transcription. AU - Walthers,Don, AU - Li,You, AU - Liu,Yingjie, AU - Anand,Ganesh, AU - Yan,Jie, AU - Kenney,Linda J, Y1 - 2010/11/08/ PY - 2010/11/10/entrez PY - 2010/11/10/pubmed PY - 2011/2/25/medline SP - 1895 EP - 902 JF - The Journal of biological chemistry JO - J Biol Chem VL - 286 IS - 3 N2 - The response regulator SsrB activates expression of genes encoded within and outside of a pathogenicity island (SPI-2), which is required for systemic infection of Salmonella. SsrB binds upstream of the sifA, sifB, and sseJ effector genes and directly regulates transcription. SsrB also relieves gene silencing by the nucleoid protein H-NS. Single molecule experiments with magnetic tweezers demonstrated that SsrB displaces H-NS from DNA only when it is bound in a polymerization (stiffening) mode and not when H-NS is bound to DNA in the bridging mode. Thus, in contrast to previous views, the polymerization binding mode of H-NS is the relevant form for counter-silencing by SsrB. Our results reveal that response regulators can directly activate transcription and also relieve H-NS silencing. This study adds to the repertoire of mechanisms by which NarL/FixJ subfamily members regulate transcription. Because SsrB-dependent promoters are diversely organized, additional mechanisms of transcriptional activation at other loci are likely. SN - 1083-351X UR - https://www.unboundmedicine.com/medline/citation/21059643/Salmonella_enterica_response_regulator_SsrB_relieves_H_NS_silencing_by_displacing_H_NS_bound_in_polymerization_mode_and_directly_activates_transcription_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0021-9258(20)56223-6 DB - PRIME DP - Unbound Medicine ER -