Faites connaître cette offre !
Reference : UMR7256-ESTGRO-003
Workplace : MARSEILLE 09
Date of publication : Monday, July 29, 2019
Type of Contract : FTC Scientist
Contract Period : 12 months
Expected date of employment : 1 October 2019
Proportion of work : Full time
Remuneration : Monthly Salary between 2750 and 3840 € depending on experience
Desired level of education : PhD
Experience required : Indifferent
The IGS laboratory is offering a Post-doctoral position to study the genome organisation of the Mimiviridae inside the icosahedral capsids. The genome is surrounded by proteins allowing the 400 µm long dsDNA to fold as a helicoidal assembly reminiscent of filamentous phages but with a larger section (30nm).This study could reveal possible evolutionary links with other known helicoidal genome structures such as the ones used by phages or archaeal viruses or even with the nuclear chromatin.
One first aim will be to purify efficiently the rod-shaped structure corresponding to the genomic fiber in order to identify the proteins which are involved in its organization using Mass spectrometry proteomics.
A protocol for releasing it efficiently from the capsids is already available but needs to be optimized. Together with a PhD student, the candidate will then express the individual proteins and determine their 3D-structures by X-ray crystallography or/and Cryo-EM. Co-expression and in vitro reconstitution experiments will also be attempted depending on the genomic fiber protein complexity as revealed by the proteomic analyses. Finally, Cryo-EM structure determination will be conducted on the native genomic fiber and on the in vitro reconstituted genome free structure. The Cryo-EM data acquisition will be performed in collaboration with the Kay Grünewald laboratory, CSSB, Hamburg, Germany). The IGS laboratory possesses all necessary computing power and has access to two imagery platforms in Marseille.
- PhD in Biological Science or Physics
- Strong expertise in structural biology: Biochemistry, CryoEM and Crystallography.
- Any citizenship
The IGS laboratory is a pioneer and a world leader in the study of giant viruses for which we discovered the four known families. A unique strength of the IGS laboratory is the coexistence of a computational biology team and an experimental biology team, allowing efficient and seamless continuity from isolation of new microorganisms to their comprehensive characterization using genomics, transcriptomics and proteomics. The laboratory also has the capacity to determine the 3D-structure of viral proteins of specific interest using X-ray crystallography alone or in combination with Electron Microscopy. An ERC advanced grant starting in October 2019 provides two post-doctoral positions and two PhD grants to study the structural organization of the genomes of the Mimiviridae and identify the machinery responsible for their packaging into rod shaped structures filling the 450nm icosahedral virions.
Constraints and risks
Constrains: Data acquisition at synchrotron are made in the context of a shared Bag which means that the applicant will have to spend time on the beamlines collecting data for the IGS but also for other members of the BAG. Missions are not frequent but can take place during nights and week-end
To apply for the Position at IGS, the candidate must send his/her CV with a complete list of publications, a motivation letter and at least one reference letter.
The selected candidate can start between the end of October 2019 and January 2020, depending on his/her availability. The position is for 1 year and can be renewed for 3 years.
The IGS laboratory is already well equipped for cellular biology (2 L2 rooms, 6 PSM, 3 fluorescence microscopes (including 1 Zeiss Axio), 4 incubators), biochemistry (PCR, 1 Microbiology PSM, 3 incubators, 2 Aktä explorer 10S, 1 Aktä 3D, 1 Aktä Prime, Nanodrop, Qubit, 96-well and 1mL spectrophotometers), and structural biology (Mosquito crystallization robot, in-house diffractometer (Oxford diffraction Xcalibur PXUltra, a speedvac SPD131 ThermoFischer). The IGS has direct access to the 12 technical platforms at the Mediterranean Institute of Microbiology (IMM, AMU-CNRS FR3479, Staff: 300). The platforms of interest for the project are fluorescence/TEM imaging (TEM, Cryo-TEM), NMR (600 MHz, cryoprobe), Proteomics, protein expression and protein interaction facility (1 Aktä prime, 1 Aktä Pure). The protein production platform runs a Blitz system used to rapidly screen and characterize macromolecular interactions. The IGS also has permanent access to the Luminy campus imagery platforms including electron microscopy (TEM and STEM) at the IBDM (Institut de Biologie du Développement de Marseille). The IGS masters all the required skills in cellular biology (light, fluorescence and electron microscopy, virus purification, synchronized infections, extraction, and molecular studies), structural biology, biochemistry and virology methods. The laboratory is also part of the Marseille synchrotron BAG and has access to European synchrotron radiation facilities and Soleil for crystallography. The Bag also provides free of charge access to the EM platforms at ESRF equipped with Titan Krios cryo-electron microscope with K2 Summit direct electron detector, a Quantum LS imaging filter and a Volta phase plate (VPP). This microscope will be run as a beamline (CM01) within the Partnership for Structural Biology (PSB) together with the microscopes located at IBS and EMBL. The Cryo-EM data acquisition will be performed in collaboration with the Kay Grünewald laboratory, CSSB, Hamburg, Germany equipped with five electron cryo-microscopes, including 2 Titan-Krios (300 keV top end, autoloader, DED, energy filter, VPP). The IGS laboratory possesses all necessary computing power (cluster with 71Nodes, 156 CPU, 828 Cores, 4700 Go, 150 To).
We talk about it on Twitter!