| Autor: |
Lai, R-Z, Han, X-S, Dahlquist, FW, Parkinson, JS |
| Jazyk: |
angličtina |
| Rok vydání: |
2017 |
| Předmět: |
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| Zdroj: |
Lai, R-Z; Han, X-S; Dahlquist, FW; & Parkinson, JS. (2017). Paradoxical enhancement of chemoreceptor detection sensitivity by a sensory adaptation enzyme. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 114(36), E7583-E7591. doi: 10.1073/pnas.1709075114. UC Santa Barbara: Retrieved from: http://www.escholarship.org/uc/item/0qr4f476 |
| Popis: |
A sensory adaptation system that tunes chemoreceptor sensitivity enables motile Escherichia coli cells to track chemical gradients with high sensitivity over a wide dynamic range. Sensory adaptation involves feedback control of covalent receptor modifications by two enzymes: CheR, a methyltransferase, and CheB, a methylesterase. This study describes a CheR function that opposes the signaling consequences of its catalytic activity. In the presence of CheR, a variety of mutant serine chemoreceptors displayed up to 40-fold enhanced detection sensitivity to chemoeffector stimuli. This response enhancement effect did not require the known catalytic activity of CheR, but did involve a binding interaction between CheR and receptor molecules. Response enhancement was maximal at low CheR:receptor stoichiometry and quantitative analyses argued against a reversible binding interaction that simply shifts the ON-OFF equilibrium of receptor signaling complexes. Rather, a short-lived CheR binding interaction appears to promote a long-lasting change in receptor molecules, either a covalent modification or conformation that enhances their response to attractant ligands. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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