2010/02/05 by Fan Bai, Richard W. Branch, Dan V. Nicolau +4 · 3 citations
Neuroscience · Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · Chemistry · #Photoreceptor and optogenetics research #Lipid Membrane Structure and Behavior #Spectroscopy and Quantum Chemical Studies #Allosteric regulation #Cooperativity #Biophysics #Chemotaxis #Bistability #Molecular motor #Conformational change #Chemistry #Allosteric enzyme #Cooperative binding #Physics #Biology #Binding site #Biochemistry #Receptor
paper · doi:10.1126/science.1182105
openalex publication_date 2010/02/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
The bacterial flagellar switch that controls the direction of flagellar rotation during chemotaxis has a highly cooperative response. This has previously been understood in terms of the classic two-state, concerted model of allosteric regulation. Here, we used high-resolution optical microscopy to observe switching of single motors and uncover the stochastic multistate nature of the switch. Our observations are in detailed quantitative agreement with a recent general model of allosteric cooperativity that exhibits conformational spread--the stochastic growth and shrinkage of domains of adjacent subunits sharing a particular conformational state. We expect that conformational spread will be important in explaining cooperativity in other large signaling complexes.