Missions

The recruited researcher will contribute to the development of a research project focused on the mechanistic study of metalloproteins belonging to the radical S-adenosylmethionine (SAM) enzyme superfamily. The enzymes under investigation are involved in diverse metabolic processes such as cofactor biosynthesis, peptide modification, post-translational modifications, and antibiotic biosynthesis. They operate via a radical-based mechanism that uses a 4Fe–4S cluster to reductively cleave SAM.
The researcher will join the Laboratory of Bioenergetics and Protein Engineering (BIP, according to its French acronym), a CNRS and Aix-Marseille University joint unit located on the CNRS campus in Marseille. They will be part of the Biophysics of Metalloproteins and Dynamic Systems team, which is particularly recognized for its work on metalloproteins using EPR spectroscopy techniques.

Activités

The recruited researcher will characterize these enzymes, prepared under various conditions, using spectroscopy, focusing on the study of their metal cofactors based on iron or cobalt found in these enzymes, as well as on trapped radical catalytic intermediates. To this end, various electron paramagnetic resonance (EPR) spectroscopy techniques will be employed (in continuous wave or pulse mode). Particular emphasis will be placed on the detailed investigation of the structure and environment of the paramagnetic species using pulse hyperfine spectroscopies (ENDOR, ESEEM/HYSCORE) at multiple microwave frequencies. This work will be complemented by the systematic quantitative analysis of experimental data through spectral simulation, in combination with the use of various substrates or analogues, and magnetic isotope enrichment (e.g., ²H, ¹³C, ¹⁵N), in order to decipher different steps of the catalytic process.

Compétences

The candidate should hold a PhD in (Bio)physics or Chemistry in which EPR spectroscopy played a major role, and should have solid experience with various EPR techniques, particularly hyperfine spectroscopies, as well as with spectral simulation (e.g., EasySpin). Experience in anaerobic sample preparation, electrochemistry, or quantum modelling (DFT) would be an asset. The recruited researcher is expected to demonstrate a strong ability to work independently (critical thinking, literature review, etc.) in a multidisciplinary and collaborative environment, a team spirit, as well as good communication skills in English and scientific writing. A basic knowledge of French would be an advantage, but is not mandatory. Participation in science outreach activities, EPR spectroscopy training, and/or (co-)supervision of interns (undergraduate or Master's level) or PhD students may also be required.

Contexte de travail

The recruited researcher will join the Laboratory of Bioenergetics and Protein Engineering (BIP), a joint research unit of CNRS and Aix-Marseille University, affiliated with the Mediterranean Institute of Microbiology (CNRS FR3479) and the Institute for Microbiology, Bioenergies and Biotechnology (IM2B) at AMU. BIP conducts research in the field of microbial bioenergetics, from the molecular to the cellular level.
The researcher's work will be part of a collaborative project locally led by Dr Stéphane Grimaldi within the “Biophysics of Metalloproteins and Dynamic Systems” team, and carried out in close partnership with the ChemSyBio team of the MICALIS Institute (Dr Olivier Berteau & Dr Alhosna Benjdia, INRAE/Université Paris-Saclay). This project is supported by several grants from the French National Research Agency (ANR).
At BIP, the researcher will benefit in particular from facilities for anaerobic handling of radical SAM enzymes, for their redox characterisation, as well as state-of-the-art EPR spectroscopy instrumentation available at the Aix-Marseille EPR Spectroscopy Center hosted within the unit — one of the main national EPR facilities in France and part of the Infranalytics analytical chemistry research infrastructure (CNRS FR2054).