New paradigms in bacterial sensorial systems and operon organization

The talk will be divided in two parts. In the first part, I will summarise a recent study showing that the human pathogen Staphylococcus aureus can be deprived of its complete sensorial TCS network and still survive under growth arrest conditions. The analysis of  S. aureus derivatives containing individual TCSs reveals that each TCS is autonomous and self-sufficient to confer the capacity to survive in a specific environmental condition. This organization fits well in current view that the number of two-component pairs is proportional to the diversity of environments in which organisms live. In the second part, i will summarise very recent results indicating the existence of a higher level of organization in operon structure, named “overlapping operon”, that consists in an operon containing a gene (or genes) that is transcribed in the opposite direction to the rest of the operon.