The source of high signal cooperativity in bacterial chemosensory arrays
Abstract
In Escherichia coli, chemoreceptors, the histidine kinase CheA, and the adaptor protein CheW form a highly networked chemotaxis signaling array that clusters at the cell poles. Arrayed chemoreceptors control multiple CheA molecules in highly cooperative responses to chemoeffector ligands, but the molecular interactions responsible for this behavior are unknown. We found that lesions affecting the interface 2 interaction between CheW and the P5 domain of CheA caused severe array clustering defects and abolished response cooperativity, demonstrating that along with its critical structural role, interface 2 is the route for transmitting signaling-related conformational changes throughout the array. It should be possible to exploit interface 2 mutants to develop more incisive experimental approaches and theoretical models for investigating the signaling mechanisms of chemosensory arrays.
- Publication:
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Proceedings of the National Academy of Science
- Pub Date:
- March 2016
- DOI:
- 10.1073/pnas.1600216113
- Bibcode:
- 2016PNAS..113.3335P