EVOGENE seminar: Allison Williams - The cryo-electron microscopy supramolecular structure of the bacterial stressosome unveils its mechanism of activation.
Allison Williams is a researcher at Institut Pasteur, Department of Microbiology in France.
How the stressosome integrates and transmits stress signals from the environment has remained elusive. The stressosome consists of multiple copies of three proteins RsbR, RsbS and RsbT, a kinase that is important for its activation. Using cryo-electron microscopy, we determined the atomic organization of the 1.8 megadalton Listeria monocytogenes stressosome at 3.38Å resolution. RsbR and RsbS are organized in a 60 protomers truncated icosahedron. A key phosphorylation site on RsbR (T209) is partially hidden by an RsbR flexible loop, whose “open” or “closed” position could modulate stressosome activity. Interaction between three glutamic acids in the N-terminal domain of RsbR and the membrane-bound mini-protein Prli42 are essential for Listeria survival to stress. Together, our data reveal the structure and function of the core assembly of the stressosome, and describe the discovery of a loop that is important for stressosome activation, paving the way towards elucidating the mechanism of signal transduction in the bacteria.
For more information: https://research.pasteur.fr/en/member/allison-williams/