Mechanisms of DNA-mediated allostery

by Prof. Enrico Carlon (Soft Matter and Biophysics, KU Leuven)

Wednesday 8 Feb 2023, 11:30 → 12:30 Europe/Rome

1/1-2 - Aula "C. Voci" (Dipartimento di Fisica e Astronomia - Edificio Marzolo)

It is well-known that proteins regulate their activities via allostery - or action at a distance - in which the binding of a ligand at one site influences the affinity for another ligand at a distal site. Although less studied than in proteins, allosteric effects have been observed in experiments with DNA as well. In these experiments two or more proteins bind at distinct DNA sites and interact indirectly with each other, via a mechanism mediated by the linker DNA molecule. We have investigated a coarse-grained mechanical model of DNA/protein interaction, which predicts three distinct mechanisms of allostery. Two of these involve an enthalphy-mediated allostery, while a third one is entropy-mediated. We find that allostery can be either attractive (leading to cooperative binding) or repulsive. We analyze experiments of DNA allostery and highlight the distinctive signatures allowing one to identify which of the proposed mechanisms fit best the data.