Adaptational assistance in clusters of bacterial chemoreceptors
نویسندگان
چکیده
منابع مشابه
Flexible Hinges in Bacterial Chemoreceptors.
Transmembrane bacterial chemoreceptors are extended, rod-shaped homodimers with ligand-binding sites at one end and interaction sites for signaling complex formation and histidine kinase control at the other. There are atomic-resolution structures of chemoreceptor fragments but not of intact, membrane-inserted receptors. Electron tomography of in vivo signaling complex arrays lack distinct dens...
متن کاملPhysical responses of bacterial chemoreceptors.
Chemoreceptors of the bacterium Escherichia coli are thought to form trimers of homodimers that undergo conformational changes upon ligand binding and thereby signal a cytoplasmic kinase. We monitored the physical responses of trimers in living cells lacking other chemotaxis proteins by fluorescently tagging receptors and measuring changes in fluorescence anisotropy. These changes were traced t...
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Four chemoreceptors in Escherichia coli mediate responses to chemicals in the environment. The receptors self-associate and localize to the cell poles. This aggregation implies that interactions among receptors are important parameters of signal processing during chemotaxis. We examined this phenomenon using a receptor-coupled in vitro assay of CheA kinase activity. The ability of homogeneous p...
متن کاملCollaborative signaling by bacterial chemoreceptors.
Motile bacteria seek optimal living habitats by following gradients of attractant and repellent chemicals in their environment. The signaling machinery for these chemotactic behaviors, although assembled from just a few protein components, has extraordinary information-processing capabilities. Escherichia coli, the best-studied model, employs a networked cluster of transmembrane receptors to de...
متن کاملEfficient adaptational demethylation of chemoreceptors requires the same enzyme-docking site as efficient methylation.
The mechanistic basis of sensory adaptation and gradient sensing in bacterial chemotaxis is reversible covalent modification of transmembrane chemoreceptors, methylation, and demethylation at specific glutamyl residues in their cytoplasmic domains. These reactions are catalyzed by a dedicated methyltransferase CheR and a dedicated methylesterase CheB. The esterase is also a deamidase that creat...
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ژورنال
عنوان ژورنال: Molecular Microbiology
سال: 2005
ISSN: 0950-382X
DOI: 10.1111/j.1365-2958.2005.04641.x