Decoding the Role of the Global Proteome Dynamics for Cellular Thermal Stability

Area of Science:

• Microbiology
• Biophysics
• Computational Biology

Background:

• The molecular basis of cellular thermal responses is not fully understood.
• Bacterial proteome dynamics correlate with temperature-dependent metabolism and survival.
• Investigating proteome mobility offers insights into cellular adaptation to temperature.

Purpose of the Study:

• To explore the sub-nanosecond proteome mobility in bacteria with varying thermal optima.
• To determine the relationship between proteome dynamics and bacterial thermal stability.
• To elucidate the role of cytoplasmic properties and proteome charge in thermal adaptation.

Main Methods:

• Neutron scattering (NS) spectroscopy to measure atomic mean square displacements.
• Molecular dynamics (MD) simulations to model proteome dynamics.
• Comparative analysis of psychrophilic, mesophilic, and hyperthermophilic bacteria.

Main Results:

• Atomic mean square displacements were similar across bacteria at their thermal death points.
• Global roto-translational motions were key differentiators of bacterial dynamical properties.
• Bacterial thermal stability correlated with a less negative average proteome net charge.

Conclusions:

• Evolution fine-tunes cytoplasmic properties and proteome dynamics for optimal thermal stability.
• Proteome net charge is a critical factor in bacterial adaptation to temperature extremes.
• Understanding proteome mobility provides a new perspective on cellular thermal response mechanisms.