Dynamique des complexes nucléoproteiques

We use multi-scale computational approaches 
to integrate multiple heterogeneous sources of experimental data to provide a detailed ensemble description of complex (large and/or disordered) nucleoprotein complexes to understand the molecular and mechanical determinants of their function.

Contacts:
Marco Pasi marco.pasi <at> ens-paris-saclay.fr
Malcolm Buckle malcolm.buckle <at> ens-paris-saclay.fr
David Perahia david.perahia <at> ens-paris-saclay.fr
 

PhAST

Nucleosome dynamicsA complex hierarchy of nucleosomes dynamics (breathing, sliding, twisting, assembly/disassembly, …) controls DNA accessibility and therefore gene expression. To study these processes we have developed an original and powerful methodology: PhAST (for Photochemical Analysis of Structural Transitions).

 

Nucleosome Assembly and DisassemblyBy measuring UV-induced photochemical changes 
in DNA at base-pair 
resolution, we quantify the effect of histone binding 
on the local structure of DNA with minimal perturbation to follow all steps of turnover in 
the same conditions. We observe for the first time “hysteresis” between assembly and disassembly, suggesting that disassembly is more cooperative than assembly {Shymko et al. 2022}

 

 

 

ABCix

logoThe ABCix project, the latest effort (2021) of the Ascona B-DNA (ABC) consortium, aims to systematically characterize of the physical properties of all 2080 unique hexanucleotides, from a collection of 950, 10μs-long MD simulations.

 

The vast simulation effort will allow the exploration of long-term dynamics of solvated duplexes to define potential frustration effects in DNA, sequence-dependent solvent and ion atmosphere, correlation and signal transfer effects, which could not be explored in previous calculations focussed in much shorter elements.

The current ABC consortium is formed by thirteen groups (the most visible ones) from Europe and US. See also the ABCix website.