Bacillus allow their metabolism to take a break during which they suppress, for example, the incorporation of proteins into membranes. Scientists from Marburg, Freiburg, and Munich have discovered this by biochemically investigating the stress response of microorganisms. In the scientific journal "Nature Communications," a researcher is assisting scientists from across the country.
Bacteria respond to stress, such as nutrient deficiency or heat, with an adaptation of their metabolism, known as the stringent response. "Second messengers or alarm hormones play a significant role in this process," Bange explains. "SRP is essential for the formation of membrane proteins and protein secretion," says Bange''s collaborator Dr. Laura Czech, who has led the publication. The particle ensures that proteins reach their proper destination in the cell''s membranes.
"So far, it was unknown to what regulatory mechanisms the signal recognition particle is subjected to," says a doctoral researcher at Bange''s lab. The research team conducted molecular biological, biochemical, and structural biological experiments to establish how alarm hormones interact with the signal recognition particle.
Electron micrographs were created at extremely low temperatures, demonstrating how SRP ties to the protein production machinery.
Alarm hormones seem to hinder the signal-recognition particle from forming a complex with other molecules, preventing it from performing its task of incorporating proteins into the membrane.
"Under harsh environmental conditions, bacterial cells may use shutting down important metabolic processes as a pause mechanism," Gert Bange says. This break allows the microorganisms to slow down their cellular processes and metabolism so they can recover as soon as conditions become more favorable. "Inhibiting the metabolic pathway leading through the signal recognition particle might be an additional level of cellular control and pausing to survive during difficult periods.