The Archaea have recently come to center stage, not only because of their key role in the origin of eukaryotes, but also as important yet neglected residents of the human microbiome.
We have recently developed the first experimental model of a host-associated archaeon, Methanobrevibacter smithii, the main species of methanogens from the human gut. We have demonstrated that M. smithii is an ovococcoid that divides binarily using a homologue of FtsZ and its anchor SepF. Interestingly, while most archaea contain a proteinaceous S-layer as major component of the cell envelope, M. smithii and its close relatives possess a cell wall made of pseudopeptidoglycan (pPG). It structurally resembles its bacterial counterpart, but is chemically distinct, indicating an independent evolutionary origin. How these archaea “reinvented” a pPG cell wall, and what were the consequences at the cellular level are fascinating open questions. In fact, the archaeal machineries involved in cell growth and division in the presence of a pPG cell wall remain largely unknown.
The project aims at identifying and characterizing additional components of the M. smithii divisome and elongasome and understanding how the cell wall is synthesized and modified during the cell cycle. A wide range of approaches will be used, including immunolabeling and high-resolution microscopy, protein-protein interaction, biochemical characterization, and bioinformatics analysis.
The results obtained will have strong impact on the rapidly expanding field of archaeal cell biology. Moreover, by identifying the elements driving cell growth and division in this major and yet neglected component of the human microbiome, the project will contribute essential information to further research on the role of archaea in health and disease.
Applicants should hold (or expect shortly) a PhD in Life Sciences and a strong background in prokaryotic cell biology and/or biochemistry.
Previous work on Archaea is not mandatory. All the necessary training to work with methanogens will be provided by the lab. Previous experience with sequence analysis is a plus, but also not strictly necessary, as all members of the group are encouraged to acquire expertise through training either by staff bioinformaticians or frequent classes at Institut Pasteur.