Date : 16/2/2010
Biomolecular Nanomanipulation Group
Institut Jacques Monod / CNRS UMR 7592
15 rue Hélène Brion Batiment Buffon 242B
75205 Paris Cedex 13
Director : Giuseppe Baldacci
phone : +33 157278020
Subjects / Tools-Methodologies
1 : DNA replication/magnetic trapping, single-molecule imaging
2 : DNA transcription/magnetic trapping, single-molecule imaging
3 : DNA repair/magnetic trapping, single-molecule imaging
Summary of lab's interests
The team is focused on elucidating the statistical and mechanistic rules underpinning a wide range of DNA-centric processes such as transcription, replication and repair. Although currently based primarily on in vitro approaches for DNA nanomanipulation, such experiments will be complemented by developping in vitro single-molecule imaging approaches for the study of fluorescently tagged proteins (ie FRET and evanescent-wave positionning). They will also be complemented by the development of in vivo single-molecule imaging, either via PALM ultraresolution microscopy for imaging of high-concentration protein components, or widefield imaging of low-concentration protein components.
Summary of project
The initiation of DNA replication is highly coordinated in time and space. In all model organisms studied -- including viruses, bacteria, and eukaryotes -- the first steps of initiation involve the assembly of a protein complex at the so-called origin of replication. In E. coli the complex is based on a single protein species, namely DnaA. In viruses well-studied proteins involved in initiation of replication include the Large T-antigen (SV40 replication) and the E1-E2 complex (Bovine Papillomavirus). In eukaryotic systems the proteins involved in the initiation of replication involve the Mini-Chromosome Maintenance/Origin Recognition Complex (MCM/ORC) families of proteins. This project aims to study the protein-DNA interactions involved in initiation of replication from both the mechanical standpoint (based on single-molecule nanomanipulation using magnetic trapping of DNA) and the statistical standpoint (based on in vivo imaging of protein components).