Hsp70 molecular chaperones are abundant ATP-dependent nanomachines that actively reshape non-native, misfolded proteins and assist a wide variety of essential cellular processes. Here, we combine complementary theoretical approaches to elucidate the structural thermodynamic details chaperone-induced expansion substrate protein, with particular emphasis on critical role played by ATP hydrolysis. We first determine conformational free-energy cost due binding multiple using coarse-grained...

Abstract Adaptation is a defining feature of living systems. The bacterial flagellar motor adapts to changes in the external mechanical load by adding or removing torque-generating (stator) units. But molecular mechanism behind this mechano-adaptation remains unclear. Here, we combine single eletrorotation experiments and theoretical modeling show that enabled multiple mechanosensitive internal states. Dwell time statistics from suggest existence at least two bound states with high low...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron-transfer equilibria and kinetics of N-alkylphenothiazines in micellar systemsEzio Pelizzetti, Emilia Fisicaro, Claudio Minero, Alberto Sassi, Hisao HidakaCite this: J. Phys. Chem. 1991, 95, 2, 761–766Publication Date (Print):January 1, 1991Publication History Published online1 May 2002Published inissue 1 January 1991https://pubs.acs.org/doi/10.1021/j100155a050https://doi.org/10.1021/j100155a050research-articleACS PublicationsRequest reuse...

The shape of a polymer plays an important role in determining its interactions with other molecules and the environment, is turn affected by both them. As consequence, literature properties chain many different conditions have been investigated. Here, we characterize orientational under tension, physical condition typically realized single-molecule experiments vivo. By means analytical calculations Monte Carlo simulations, develop theoretical framework which quantitatively describes these...

Significance Stochastic pulsatile dynamics are ubiquitous in organisms ranging from Escherichia coli to mammalian cells. The molecular mechanism for these stochastic pulses has long been thought depend on feedback control that leads bistability the underlying system. Here, by quantitative modeling constrained recent single-cell data E. flagellar synthesis, we find an inhibitor of transcription factor creates a monotonic ultrasensitive switch serves as digital filter eliminate small-amplitude...

Protein concentration in a living cell fluctuates over time due to noise growth and division processes. In the high expression regime, variance of protein is found scale with square mean, which belongs general phenomenon called Taylor's law (TL). To understand origin for these fluctuations, we measure dynamics single Escherichia coli cells from set strains variable fluorescent proteins. The controlled by constitutive promoters different strength, allows one change level 2 orders magnitude...

Abstract Protein homeostasis, namely the ensemble of cellular mechanisms collectively controlling activity, stability and conformational states proteins, depends on energy-consuming processes. De novo protein synthesis requires ATP hydrolysis for peptide bond formation. Controlled degradation by chaperone-gated proteases to unfold target proteins render their bonds accessible hydrolysis. During following translation, different classes molecular chaperones require control state favor folding...

Protein concentration in a living cell fluctuates over time due to noise growth and division processes. From extensive single-cell experiments by using E. coli strains with different promoter strength (over two orders of magnitude) under nutrient conditions, we found that the variance protein fluctuations follows robust square power-law dependence on its mean, which belongs general phenomenon called Taylor's law. To understand mechanistic origin this observation, use minimal model describe...

Adaptation is a defining feature of living systems. The bacterial flagellar motor adapts to changes in the external mechanical environment by adding or removing torque-generating stator units. However, molecular mechanism for mechanosensitive remodeling remains unclear. Here, we induced disassembly using electrorotation, followed time-dependent assembly individual units into after electrorotation was terminated. From these experiments, extracted detailed statistics dwell times that comprise...

Hsp70 molecular chaperones are abundant ATP-dependent nanomachines that actively reshape non-native, misfolded proteins and assist a wide variety of essential cellular processes. Here we combine complementary computational/theoretical approaches to elucidate the structural thermodynamic details chaperone-induced expansion substrate protein, with particular emphasis on critical role played by ATP hydrolysis. We first determine conformational free-energy cost due binding multiple using...

Stochastic pulsatile dynamics have been observed in an increasing number of biological circuits with typical mechanism involving feedback control. Surprisingly, recent single-cell experiments showed that E. coli flagellar class-2&3 promoters are activated stochastic pulses without the means feedback, however, underlying design principles pulse generation remained unclear. Here, by developing a system-level model constrained large set synthesis data from different strains and mutants, we...