Doctorate on the Xer site-specific recombination system (M/F)

CNRS; France; Sur place; EUR 30 000 - 45 000; Plein temps

Résumé du poste

A leading research institution in France is seeking a full-time Researcher to work in the Evolution and Maintenance of Circular Chromosomes team. This position focuses on elucidating molecular interactions controlling Xer recombination using a variety of advanced techniques. Applicants should have an understanding of biological sciences, particularly in the area of molecular genetics and biochemistry. The role is set to start on February 1, 2026, and offers a temporary contract.

Qualifications

• Experience with molecular interactions and recombination systems is relevant.
• Understanding of genetic and biochemical experiments is necessary.

Responsabilités

• Elucidate molecular interactions controlling Xer recombination.
• Combine crystallography and cryoEM techniques.
• Conduct in vitro biochemical and in vivo molecular genetics assays.

Description du poste

Organisation/Company CNRS Department Institut de Biologie Intégrative de la Cellule Research Field Chemistry » Biochemistry Physics » Biophysics Biological sciences » Biological engineering Researcher Profile First Stage Researcher (R1) Country France Application Deadline 5 Dec 2025 - 23:59 (UTC) Type of Contract Temporary Job Status Full-time Hours Per Week 35 Offer Starting Date 1 Feb 2026 Is the job funded through the EU Research Framework Programme? Not funded by a EU programme Is the Job related to staff position within a Research Infrastructure? No

Offer Description

Work will be undertaken in the Evolution and Maintenance of Circular Chromosomes team in the genome biology department of the Institute of Integrative Cell Biology (I2BC). The Instirute is located in the CNRS campus of Gif sur Yvette.

Elucidation of the molecular Interactions controlling Xer recombination
Bacteria have evolved a highly conserved tyrosine recombination machinery, Xer, to resolve chromosome dimers by adding a crossover at a specific site, dif. Xer also mediates the integration of many mobile elements into their host genome by recombining dif and a dif-like attachment site, attP, carried by the mobile element. Two features distinguish the Xer system from paradigmatic tyrosine recombination systems. First, tyrosine recombination systems are generally composed of a single tyrosine recombinase. In contrast, with the exception of a few species, Xer is composed of two tyrosine recombinases, XerC and XerD, which each bind to a specific arm of the recombination sites and catalyse the exchange a specific pair of strands . Thus, two recombination pathways can be considered, depending on whether XerC or XerD initiates the recombination reaction. Second, XerD is inactive by default. The integration of various phages exploiting Xer, including the Vibrio cholerae Cholera-ToXin phage (CTXΦ), is initiated by XerC. However, chromosome dimer resolution and the integration of the V. cholerae Toxin-Linked Crytic phage satellite (TLCΦ) both depend on the XerD-first pathway. Genetic and biochemical experiments have shed light on the protein factors that control the XerC and XerD-first pathways. The aim of the doctoral elucidate the molecular interactions that control Xer recombination by an integrative approach combining crystallography, cryoEM, in vitro biochemical assays and in vivo molecular genetics assays.

Research Field Biological sciences » Biological engineering Years of Research Experience None