McsB forms a gated kinase chamber to mark aberrant bacterial proteins for degradation
- Research Institute of Molecular Pathology, Austria
- University of Oxford, United Kingdom
- Ludwig Maximilian University of Munich, Germany
Abstract
In Gram-positive bacteria, the McsB protein arginine kinase is central to protein quality control, labelling aberrant molecules for degradation by the ClpCP protease. Despite its importance for stress response and pathogenicity, it is still elusive how the bacterial degradation labelling is regulated. Here, we delineate the mechanism how McsB targets aberrant proteins during stress conditions. Structural data reveal a self-compartmentalized kinase, in which the active sites are sequestered in a molecular cage. The 'closed' octamer interconverts with other oligomers in a phosphorylation-dependent manner and, contrary to these 'open' forms, preferentially labels unfolded proteins. In vivo data show that heat-shock triggers accumulation of higher-order oligomers, of which the octameric McsB is essential for surviving stress situations. The interconversion of open and closed oligomers represents a distinct regulatory mechanism of a degradation labeler, allowing the McsB kinase to adapt its potentially dangerous enzyme function to the needs of the bacterial cell.
Data availability
Structure factor amplitudes and Coordinate files have been deposited in the Protein Data Bank under the accession number 6TV6.
Article and author information
Author details
Funding
H2020 European Research Council (AdG 694978)
- Tim Clausen
FFG (Headquarter Grant 852936)
- Tim Clausen
H2020 European Research Council (CoG 819593)
- Philipp Kukura
Deutsche Forschungsgemeinschaft (Return Grant HU 2462/3-1)
- Nikolas Hundt
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Hajdusits 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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McsB forms a gated kinase chamber to mark aberrant bacterial proteins for degradation
eLife 10:e63505.
https://doi.org/10.7554/eLife.63505
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