Receptor-Receptor Coupling in Bacterial Chemotaxis: Evidence for Strongly Coupled Clusters

• Published in: Biophysical journal 2006-06, Vol.90 (12), p.4317-4326
• Main Authors: Skoge, Monica L., Endres, Robert G., Wingreen, Ned S.
• Format: Article
• Language: English
• Subjects: Bacteria; Binding Sites; Biophysical Theory and Modeling; Biophysics; Chemotactic Factors - chemistry; Chemotactic Factors - pharmacology; Chemotaxis - physiology; Cluster Analysis; Escherichia coli; Escherichia coli - chemistry; Escherichia coli - drug effects; Escherichia coli - physiology; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - metabolism; Evidence-Based Medicine; Fluorescence; Models, Biological; Models, Chemical; Models, Molecular; Protein Binding; Proteins; Receptors, Cell Surface - chemistry; Receptors, Cell Surface - metabolism
• ISSN: 0006-3495; 1542-0086
• DOI: 10.1529/biophysj.105.079905

Receptor coupling is believed to explain the high sensitivity of the Escherichia coli chemotaxis network to small changes in levels of chemoattractant. We compare in detail the activity response of coupled two-state receptors for different models of receptor coupling: weakly-coupled extended one-dimensional and two-dimensional lattice models and the Monod-Wyman-Changeux model of isolated strongly-coupled clusters. We identify features in recent data that distinguish between the models. Specifically, researchers have measured the receptor activity response to steps of chemoattractant for a variety of engineered E. coli strains using in vivo fluorescence resonance energy transfer. We find that the fluorescence resonance energy transfer results for wild-type and for a low-activity mutant are inconsistent with the lattice models of receptor coupling, but consistent with the Monod-Wyman-Changeux model of receptor coupling, suggesting that receptors form isolated strongly-coupled clusters.