New work from Saint Louis University has uncovered the way a bacterial ribosome moves from an inactive to an active form, and how that "wake up call" is key to its survival. The findings were published in Proceedings of the National Academy of Sciences earlier this week.
Protein synthesis takes up more than 50% of a bacteria cell's energy costs. So in order to conserve energy when conditions are unfavorable, bacteria shut down their protein factory, the ribosome, and take an inactive state called hibernating 100S ribosome.
In this study, the scientists observed that the hibernating form of the ribosome is not a permanent state and that if conditions are favorable. The ribosome can "wake up" and return to the active form called 70S.
Mee-Ngan F. Yap, Ph.D., an assistant professor of biochemistry and molecular biology at Saint Louis University, was looking for the protein factor that caused the 100S form to return to the intermediate 30S and 50S forms and subsequently into the active 70S form. By studying Staphylococcus aureus, Yap found that a GTP hydrolase enzyme called HflX is the wake-up call that will re-activate the ribosome.
HflX GTPases are a family of enzymes that are evolutionarily conserved proteins. Yap is intrigued by this finding, because while there has been virtually no study of the protein in human cells, it appears in genetic sequencing mapped to cancer patients and those with neurological symptoms, including tic disorder-like syndromes. Scientists do not yet know what this connection means.
For now, Yap will continue to look more in depth for questions related to the hibernating ribosomes' role in cell survival.