Regulation of signaling directionality revealed by 3D snapshots of a kinase:regulator complex in action
- Institut Pasteur de Montevideo, Uruguay
- Universidad de Buenos Aires, Argentina
Abstract
Two-component systems (TCS) are protein machineries that enable cells to respond to input signals. Histidine kinases (HK) are the sensory component, transferring information toward downstream response regulators (RR). HKs transfer phosphoryl groups to their specific RRs, but also dephosphorylate them, overall ensuring proper signaling. The mechanisms by which HKs discriminate between such disparate directions, are yet unknown. We now disclose crystal structures of the HK:RR complex DesK:DesR from Bacillus subtilis, comprising snapshots of the phosphotransfer and the dephosphorylation reactions. The HK dictates the reactional outcome through conformational rearrangements that include the reactive histidine. The phosphotransfer center is asymmetric, poised for dissociative nucleophilic substitution. The structural bases of HK phosphatase/phosphotransferase control are uncovered, and the unexpected discovery of a dissociative reactional center, sheds light on the evolution of TCS phosphotransfer reversibility. Our findings should be applicable to a broad range of signaling systems and instrumental in synthetic TCS rewiring.
Data availability
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Crystal structure of phosphorylated DesKCPublicly available at the RCSB Protein Data Bank (accession no: 5IUM).
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Crystal structure of the DesK-DesR complex in the phosphatase statePublicly available at the RCSB Protein Data Bank (accession no: 5IUN).
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Crystal structure of the DesK-DesR complex in the phosphotransfer state with low Mg2+ (20 mM)Publicly available at the RCSB Protein Data Bank (accession no: 5IUJ).
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Crystal structure of the DesK-DesR complex in the phosphotransfer state with high Mg2+ (150 mM)Publicly available at the RCSB Protein Data Bank (accession no: 5IUK).
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Crystal structure of the DesK-DesR complex in the phosphotransfer state with high Mg2+ (150 mM) and BeF3Publicly available at the RCSB Protein Data Bank (accession no: 5IUL).
Article and author information
Author details
Alejandro Buschiazzo
Funding
Agencia Nacional de Investigación e Innovación (FCE2009_1_2679)
- Felipe Trajtenberg
- Alejandro Buschiazzo
Agence Nationale de la Recherche (PCV06_138918)
- Alejandro Buschiazzo
FOCEM (COF 03/11)
- Alejandro Buschiazzo
Centro de Biologia Estructural del Mercosur
- Alejandro Buschiazzo
Agencia Nacional de Investigación e Innovación (FCE2007_219)
- Felipe Trajtenberg
- Alejandro Buschiazzo
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2016, Trajtenberg et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Regulation of signaling directionality revealed by 3D snapshots of a kinase:regulator complex in action
eLife 5:e21422.
https://doi.org/10.7554/eLife.21422
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