Role of the PFXFATG[G/Y] Motif in the Activation of SdrG, a Response Regulator Involved in the Alphaproteobacterial General Stress Response.

Two-component systems are major signal transduction pathways, which consist of histidine kinases and response regulators that communicate through phosphorylation. Here, we highlight a distinct class of single-domain response regulators containing the PFXFATG[G/Y] motif that are activated by a mechanism distinct from the Y-T coupling described for prototypical receiver domains. We first solved the structures of inactive and active SdrG, a representative of the FAT GUY family, and then biochemically and genetically characterized variants in which residues in this motif were mutated. Our results support a model of activation mainly driven by a conserved lysine and reveal that the rotation of the threonine induces the reorganization of several aromatic residues in and around the PFXFATG[G/Y] motif to generate intermediates resembling those occurring during classical Y-T coupling. Overall, this helps define a new subfamily of response regulators that emerge as important players in physiological adaptation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Citation

Sébastien Campagne, Sebastian Dintner, Lisa Gottschlich, Maxence Thibault, Miriam Bortfeld-Miller, Andreas Kaczmarczyk, Anne Francez-Charlot, Frédéric H-T Allain, Julia A Vorholt. Role of the PFXFATG[G/Y] Motif in the Activation of SdrG, a Response Regulator Involved in the Alphaproteobacterial General Stress Response. Structure (London, England : 1993). 2016 Aug 2;24(8):1237-47

PMID: 27396826

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