Offre de thèse
CD Amélioration de la spécificité de substrat des domaines d'une acide gras synthase par la reconstruction de séquences ancestrales : applications en ingénierie
Date limite de candidature
10-06-2025
Date de début de contrat
01-10-2025
Directeur de thèse
WEISSMAN - SOURMAIL Kira
Encadrement
During the PhD, the student will benefit not only from close, hands-on supervision by the three supervisors (KJ Weissman, A Gruez (UL); M Grininger (GUF)), but also from interaction with and scientific support from other members of the two laboratories with complementary competences. Regular intra-laboratory meetings will be scheduled to follow the progress of the research, as well as bi-yearly inter-lab sessions (alternating between the UL and GUF) to address the overall health and functioning of the collaboration, as well as any administrative requirements (e.g. conventions de co-tutelle/formation, accord de partenariat, etc.). As is systematic in our groups, the PhD student will have regular opportunities to present his/her work in the form of group seminars, posters and talks (with significant effort from the supervisors to aid in preparation), as well as at several conferences, in either oral or poster format (typically one national and one international (e.g. Directing Biosynthesis VIII, 2026). In both Universities, the student will be integrated into a graduate school, both of which have mechanisms in place to ensure that the thesis is completed successfully and all administrative and training formalities are met (UL: BioSE; GUF: GRADE).
Type de contrat
école doctorale
équipe
Equipe 3 : Enzymologie Redox Multiéchelle et Epitranscriptomique (EpiRedOx)contexte
Both FAS and PKS systems are promising engineering targets. FASs are extensively utilized for the microbial production of fatty acids and their derivatives. These platform chemicals already play a key role in reducing our reliance on crude oil and energy-intensive synthetic processes. Concerning the polyketides, many of these metabolites are employed in human and veterinary medicine and in agrochemistry, but derivatives are increasingly being developed as both fine and commodity chemicals. It is thus of substantial interest to improve our ability to reconfigure both FASs and PKSs towards the high-yield production of platform chemicals, as well as bioactive compounds with enhanced medicinal properties.spécialité
Sciences de la Vie et de la Santé - BioSElaboratoire
IMoPA - Ingénierie Moléculaire et Physiopathologie Articulaire
Mots clés
Acide gras synthases, polycétides synthases, kétosynthase, malonyl-acétyle transférase, biologie synthétique
Détail de l'offre
Les polykétide synthases modulaires (PKS) et les synthases d'acides gras de mammifères (mFAS) sont de gigantesques multienzymes dont les domaines constitutifs catalysent une chimie similaire. Les efforts de réingénierie de ces deux types de systèmes en vue de générer de nouveaux dérivés de grande valeur sont actuellement limités par la spécificité intrinsèque du substrat de certains domaines. Dans ce contexte, ce projet de doctorat en collaboration franco-allemande (co-tutelle) vise à déterminer si la reconstruction de séquences ancestrales (ASR) appliquée aux domaines de la cétosynthase (KS) et de la malonyl-acétyl-transférase (MAT) du mFAS, produit des enzymes qui peuvent être introduites à la fois dans les PKS et les FAS afin de surmonter cette barrière de spécificité. La fonctionnalité des domaines reconstruits sera évaluée dans les deux laboratoires en utilisant une combinaison d'essais in vitro, de biologie structurale/modélisation moléculaire et de génie génétique.
Keywords
fatty acid synthase, polyketide synthases, ketosynthase, malonyl-acetyl transferase, synthetic biology
Subject details
Modular polyketide synthases (PKSs) and mammalian fatty acid synthases (mFASs) are gigantic multienzymes whose component domains catalyze analogous chemistry. Efforts to re-engineer both types of systems towards the generation of novel, high-value derivatives are currently limited by the intrinsic substrate specificity of certain domains. In this context, this collaborative French-German (co-tutelle) PhD project aims to determine whether ancestral sequence reconstruction (ASR) applied to the ketosynthase (KS) and malonyl-acetyl transferase (MAT) domains of mFAS, yields enzymes which can be introduced into both PKSs and FASs to overcome this specificity barrier. The functionality of the reconstructed domains will be assessed in the two labs using a combination of in vitro assay, structural biology/molecular modeling and genetic engineering.
Profil du candidat
Idéalement, le candidat recruté aura de solides connaissances de base en chimie.
Candidate profile
The recruited candidate will ideally have a strong basic knowledge of chemistry.
Référence biblio
1. Grininger, M. Enzymology of assembly line synthesis by modular polyketide synthases. Nat Chem Biol 1–15 (2023) doi:10.1038/s41589-023-01277-7.
2. Weissman, K. J. The structural biology of biosynthetic megaenzymes. Nat. Chem. Biol. 11, 660–670 (2015).
3. Weissman, K. J. Genetic engineering of modular PKSs: from combinatorial biosynthesis to synthetic biology. Nat Prod Rep (2016) doi:10.1039/c5np00109a.
4. Rittner, A., Paithankar, K. S., Drexler, D. J., Himmler, A. & Grininger, M. Probing the modularity of megasynthases by rational engineering of a fatty acid synthase Type I. Protein Science 28, 414–428 (2019).