An international collaboration coordinated by the Yaser Hashem team at the Institute of Molecular and Cellular Biology reveals the structure of ribosome dimmers of the pathogen Staphylococcus by electronic cryomicroscopy. This work allows visualizing the role of a bacterial stress response factor in the architecture of this assemblage specific to certain bacteria and opening the way to targeted therapies to fight Staphylococcus aureus infections. This study was published on June 23, 2017 in the journal The EMBO Journal.

golden staphylococcus

The thick arrows point upwards to the corresponding parts of SaHPF, the specific protein responsible for this very particular disome assembly. The thin arrows pointing to the left emphasize the role of in stopping the translation process as well as protection against antibiotics, preventing the interaction of ribosomes with mRNAs and tRNAs as well as with different families of anti- Antibiotics, respectively.

With a time, relatively short generation of the order of tens of minutes, the bacteria have a capacity to evolve much faster than that of mammals. This innate advantage in their adaptation to the environment partly explains the emergence eventually of resistance or defense mechanisms in response to many types of stresses such as nutrient depletion heat shock and Antibiotic treatment.

One of these phenomena is the standby of machinery for the synthesis of proteins by dimerization. In all living organisms, protein synthesis is controlled by ribosomes. In bacteria, it is an assembly of more than 50 proteins with three long chains of ribonucleic acids, for a total mass about 100 times greater than the average size of a protein. We know from the work done by the Nobel Prize winner Jim Watson in the 1950s that bacterial ribosomes have the ability to associate dimers within bacteria.

Work that is more recent has shown that this two-by-two arrangement of ribosomes is accompanied by a halt in protein synthesis, much like a company that has temporarily suspended its activity while waiting for better economic conditions. Unlike a limited number of bacteria, such as the classical study model Escherichia coli Staphylococcus aureus has only one longer hibernation factor.

Only a part of which is similar to that already well characterized in E. Examination of the structure at quasi-atomic resolution shows that in S. aureus, as in all other species of bacteria, the conserved part of the hibernation factor prevents the binding of other partners necessary for the synthesis of proteins.