%0 Conference Paper
%F Oral 
%T Architecture of a bacterial DNA segregation apparatus: active caging of ParB by stochastic self-assembly nucleated from the centromere
%+ Laboratoire Charles Coulomb (L2C)
%A Walter, Jean-Charles
%< sans comité de lecture
%Z L2C:14-447
%B Advanced Workshop on Interdisciplinary Views in Chromosome Structure and Function
%C Trieste, Italy
%8 2014-09-15
%D 2014
%Z Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph]Conference papers
%X Many canonical processes in molecular biology rely on the dynamic assembly of higher-order nucleoprotein complexes. In bacteria, the assembly mechanism of ParABS, the nucleoprotein super-complex that actively segregates the bacterial chromosome and many plasmids, remains elusive. We combined super-resolution microscopy, quantitative genome-wide surveys, biochemistry, and mathematical modeling to investigate the assembly of ParB at the centromere-like sequences parS. We found that nearly all ParB molecules are actively confined around parS by a network of synergistic protein-protein and protein-DNA interactions. Interrogation of the empirically determined, high-resolution ParB genomic distribution with modeling suggests that instead of binding only to specific sequences and subsequently spreading, ParB binds stochastically around parS over long distances. We propose a new model for the formation of the ParABS partition complex based on nucleation and caging: ParB forms a dynamic lattice with the DNA around parS. This assembly model and approach to characterizing large-scale, dynamic interactions between macromolecules may be generalizable to many unrelated machineries that self-assemble in superstructures.
%G English
%L hal-02025129
%U https://hal.science/hal-02025129
%~ CNRS
%~ L2C
%~ MIPS
%~ UNIV-MONTPELLIER
%~ UM-2015-2021