RNA Sequence, Structure & Function
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Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA
Campus du CNRS
Bâtiment 26
1, avenue de la terrasse
91190 Gif-sur-Yvette
FRANCE
Scientific Interest
We study the structure, function and evolution of mobile group II introns through a multidisciplinary approach that combines phylogenetic analyses, molecular biology and X-ray crystallography. Group II introns form the most abundant class of retrotransposons in bacteria and as such they play a major role in the diversification and evolution of bacterial genomes. These elements are also widespread in the organelles (mitochondria and chloroplasts) of plants, algae and fungi. The mobile group II intron is a composite element formed by a large, highly structured, self-splicing catalytic RNA interrupted by an open reading frame encoding a multifunctional reverse transcriptase. The combined activities of the self-splicing ribozyme core and its reverse transcriptase operate the intron’s retrotransposition in a highly efficient and site-specific manner. Remarkably, the structural and functional characteristics of mobile group II introns suggest that they are the ancestors of the nuclear introns, the spliceosome and the eukaryotic non-LTR retrotransposons among which, the human LINE-1 elements. We use genetic, biochemical and structural (X-ray crystallography) approaches to (i) characterize the variety of molecular strategies allowing the dissemination of group II introns within and between genomes and (ii) determine the functional impact of these introns on the host cell. Collectively, these studies will deepen our understanding of the role of group II introns in the dynamics and evolution of bacterial genomes and will shed light on the question of the evolutionary links between prokaryotic and eukaryotic retrotransposons.
We study the structure, function and evolution of mobile group II introns through a multidisciplinary approach that combines phylogenetic analyses, molecular biology and X-ray crystallography. Group II introns form the most abundant class of retrotransposons in bacteria and as such they play a major role in the diversification and evolution of bacterial genomes. These elements are also widespread in the organelles (mitochondria and chloroplasts) of plants, algae and fungi. The mobile group II intron is a composite element formed by a large, highly structured, self-splicing catalytic RNA interrupted by an open reading frame encoding a multifunctional reverse transcriptase. The combined activities of the self-splicing ribozyme core and its reverse transcriptase operate the intron’s retrotransposition in a highly efficient and site-specific manner. Remarkably, the structural and functional characteristics of mobile group II introns suggest that they are the ancestors of the nuclear introns, the spliceosome and the eukaryotic non-LTR retrotransposons among which, the human LINE-1 elements. We use genetic, biochemical and structural (X-ray crystallography) approaches to (i) characterize the variety of molecular strategies allowing the dissemination of group II introns within and between genomes and (ii) determine the functional impact of these introns on the host cell. Collectively, these studies will deepen our understanding of the role of group II introns in the dynamics and evolution of bacterial genomes and will shed light on the question of the evolutionary links between prokaryotic and eukaryotic retrotransposons.
