We invite applications for a 2-year post-doctoral position to join a collaborative project on the cell envelope of the Negativicutes: Firmicutes with an LPS-outer membrane.
A 24 months post-doctoral position is open in the team of Simonetta Gribaldo at the Institut Pasteur, Paris (https://research.pasteur.fr/en/team/group-simonetta-gribaldo/).
In our group, we study the diversity and evolution of microorganisms and their main cellular processes by using phylogenomics approaches. We have recently addressed one of the most important transitions in the history of Bacteria: that between cell envelopes with one membrane (monoderm) or two membranes (diderm). We focused on the Negativicutes, members of the Firmicutes (low G+C Gram-positives) that surprisingly display an outer membrane (OM) with LPS. Phylogenomic analysis and annotation of potential OM systems has revealed that the Negativicutes may retain an ancient diderm cell envelope that was present in the ancestor of all Firmicutes, and that monoderm lineages in this phylum arose from OM loss . We are now moving on to complement our evolutionary analyses with experimental characterization of these understudied bacteria .
The position is offered in the frame of the Fir-OM project funded by the French National Agency for Research (ANR), in collaboration with the team of Christophe Beloin (Unit “Genetics of Biofilms”, IP).
The project aims at further characterizing the cell envelope of diderm Firmicutes by using as model Veillonella, anaerobic members of the Negativicutes that are common components of the human microbiome (mouth, gut, lung, vagina) and opportunistic pathogens.
We will (i) obtain additional sequence data from the Negativicutes to better understand the origin of their OM and the evolutionary links with their closely related monoderm relatives, (ii) study the role of OM components in the capacity of Veillonella to grow as biofilms and interact with other relevant members of the gut microbiota, and (iii) characterize for the first time a number of candidate OM proteins identified through comparative genomics and proteomics, which are potentially involved in the diderm/monoderm transition or represent new systems for the biogenesis and functioning of the cell envelope.
The hired post-doc will specifically work on axis (iii). By using recently developed genetic tools for Veillonella, she/he will perform targeted mutagenesis of candidate proteins and analysis of the resulting phenotypes. These proteins will be tagged and expressed both in E. coli and V. parvula to study their cellular localization and functional interactions.
The candidate should hold a PhD, and be highly motivated to take on a scientific challenge with the development of a new model of the bacterial cell envelope. The postdoctoral fellow will interact with a consortium of complementary expertise (experimental/bioinformatics). She/he will have good experience in molecular biology and bacterial genetics. Previous experience with membrane proteins and/or manipulation of anaerobes is welcome. Depending on background and ambitions, the postdoctoral fellow will have the possibility to complement experimental work by in silico analysis, or be keen to learn from the other members of the group the principles of phylogenomics. Finally, a strong interest in microbial evolution and vivid scientific curiosity are essential qualities for this position.
Starting date can be as early as January 2018 and should be filled not later than summer 2018.
Please send a motivation letter including a brief statement of research experience, technical expertise and interest for the project, a full CV and list of publications and the contact detail of three referees to Simonetta Gribaldo (simonetta.gribaldo_at_pasteur.fr).
- Antunes LS, Poppleton D, Klingl A, Criscuolo C, Dupuy B, Brochier-Armanet C, Beloin C, and Gribaldo S (2016) Phylogenomic analysis supports the ancestral presence of LPS outer membranes in the Firmicutes. eLife 2016;5:e14589.
- Poppleton DI, Duchateau M, Hourdel V, Matondo M, Flechsler J, Klingl A, Beloin C, and Gribaldo S (2017) Outer membrane proteome of Veillonella parvula: a diderm Firmicute of the human microbiome. Front Microbiol 8:1215.