IGS – Laboratoire Information Génomique et Structurale
The labs
- AFMB - Architecture et Fonction des Macromolécules Biologiques
- BBF - Biodiversité et Biotechnologie Fongiques
- BIAM - Bioscience and Biotechnology Institute of Aix-Marseille
- BIP - Laboratoire de Bioénergétique et Ingénierie des Protéines
- IGS - Laboratoire Information Génomique et Structurale
- IMM - Institut de Microbiologie de la Méditerranée
- iSm2 - Institut des Sciences Moléculaires de Marseille - BiosCiences
- LCB - Laboratoire de Chimie bactérienne
- LISM - Laboratoire d'Ingénierie des Systèmes Macromoléculaires
- MCT - Membranes et Cibles Thérapeutiques
- MIO - Mediterranean Institute of Oceanography - Environmental Microbiology and Biotechnology
Key Figures
- 4 Teams
- 1 Facility
- 3 Researchers
- 2 Teacher-researchers and 1 Emeritus Professor
- 9 Permanent Engineers/Technicians and 2 in CDD
- 5 Post-doctoral researcher
- 2 Doctoral students
Research
The IGS lab was founded in 1995, bringing together expertise in structural biology, genomics and bioinformatics. For a decade, the lab has been a pioneer in the sequencing of numerous bacterial genomes, structural genomics and in the development of bioinformatics tools to conduct these studies. Following its involvement in the discovery of the first giant virus, Mimivirus, the lab then focused on the study of this new kind of viruses, anticipating that a large part of the virosphere was largely unexplored because of standard virus isolation protocols (i.e. filtration). Our intuition was that the astonishing properties of giant viruses might shed some light on the origin of the cellular world. Following the sampling of various environments, we discovered new strains of the Mimiviridae family in addition to prototypes of new giant viruses’ families: Pandoravirus salinus, Pithovirus sibericum and Mollivirus sibericum. The latter two were isolated from 30000 years old permafrost samples. While still looking for new giant viruses in the environment, we now mostly focus on the understanding of the cellular and molecular processes involved in giant viruses’ replication, thus the function of their genes most of which have no homolog in the contemporary cellular world.
The Teams
Giant viruses’ biology – Heads: Chantal Abergel
One of the questions addressed by the discovery of giant viruses infecting Acanthamoeba is their evolutionary origin. Where do these thousands of original proteins come from, what are their roles during the giant viruses’ infectious cycles which are for some of them cytoplasmic while others have a nuclear stage? Are they the remains of original metabolic pathways selected by ancestral proto-cells and not selected by LUCA? We combine biochemistry, structural biology with cellular biology to address the precise function of some selected proteins. We also study genome organization and packaging into the viral capsids to determine the contribution of viruses and cell to each other evolution.
Genomics and diversity of giant viruses – Heads: Matthieu Legendre
Our team investigates the diversity, evolution and genomic regulations of giant viruses. Why do these viruses encode so many genes in their genomes? How do they evolve? How they are regulated? What interactions do they establish with their hosts and the other parasites? Here are the key questions we seek to address. We use several types of “omics” data to study giant viruses, including genomics, metagenomics, transcriptomics, proteomics and epigenomics. We work in close collaboration with the other teams in the lab to combine these “omics”/bioinformatics approaches with experimental approaches
Metalloproteins in giant viruses – Heads: Elsa Garcin
Research in our team focuses on proteins from giant viruses that possess no homolog in the viral or cellular world. These viruses use iron-loaded proteins during their infectious cycle, and a large proportion of their proteins are rich in cysteines and present in the virions. We hypothesized that these proteins may contain unique iron-sulfur clusters and belong to unique metabolic pathways. For this project, we combine interdisciplinary approaches including bioinformatics, cell biology, biochemistry, biophysics, and structural biology. The elucidation of new cellular and metabolic pathways in giant viruses will be of outstanding interest for the fields of virology, evolutionary biology, and biology. The discovery of proteins with novel fold, function, and chemistry may provide new biotechnology tools, similar to bacterial restriction enzymes used in molecular biology, or the CrispR/cas system used in genetic studies.
Giant viruses’ mobilome – Heads: Sandra Jeudy
The revolutionary discovery of Mimivirus, the first virus visible under a light microscope, initiated a totally new research area in virology. Over the past 15 years, about 100 additional members of the Mimiviridae family have been isolated from various environments, among which about 1/3 have been fully sequenced. The Mimiviridae share the ability to develop a transitory organelle in the host cytoplasm, the viral factory. It was soon discovered that this specific viral organelle can be itself the target of a viral infection by smaller viruses that were called virophages. They use the same regulatory elements as their host virus and thus are able to hijack the viral factory for their own replication. Besides virophage infection, members of the Mimiviridae family were found associated to another class of mobile DNA elements called transpovirons, making their mobilome uniquely complex among the known families of large DNA viruses. This raises the question of the role of each partner in this “ménage à quatre” (host/virus/virophage/transpoviron) and their contribution to the history and evolution of the Mimiviridae. Our team combines different approaches (proteomic, transcriptomic, structural, functional and cellular studies) in order to understand the role of the mobilome’s proteins and the nature and specifity of their interactions in this intricate relationship.
IGS contacts
IGS website- +33 (0)4 91 82 54 20
- +33 (0)4 91 82 54 21
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IGS – UMR7256
Parc Scientifique de Luminy – 163 Avenue de Luminy – Case 934
13288, Marseille cedex 09, France