The CTPase activity of ParB determines the size and dynamics of prokaryotic DNA partition complexes
Abstract
ParB-like CTPases mediate the segregation of bacterial chromosomes and low-copy number plasmids. They act as DNA-sliding clamps that are loaded at parS motifs in the centromere of target DNA molecules and spread laterally to form large nucleoprotein complexes serving as docking points for the DNA segregation machinery. Here, we solve crystal structures of ParB in the pre- and post-hydrolysis state and illuminate the catalytic mechanism of nucleotide hydrolysis. Moreover, we identify conformational changes that underlie the CTP- and parS-dependent closure of ParB clamps. The study of CTPase-deficient ParB variants reveals that CTP hydrolysis serves to limit the sliding time of ParB clamps and thus drives the establishment of a well-defined ParB diffusion gradient across the centromere whose dynamics are critical for DNA segregation. These findings clarify the role of the ParB CTPase cycle in partition complex assembly and function and thus advance our understanding of this prototypic CTP-dependent molecular switch.
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BibTeX
@article{osoriovaleriano2026ctpase,
title = {{The CTPase activity of ParB determines the size and dynamics of prokaryotic DNA partition complexes}},
author = {Manuel Osorio-Valeriano and Florian Altegoer and Chandan K. Das and Wieland Steinchen and Gaël Panis and Lara Connolley and Giacomo Giacomelli and Helge Feddersen and Laura Corrales-Guerrero and Pietro I. Giammarinaro and Juri Hanßmann and Marc Bramkamp and Patrick H. Viollier and Seán Murray and Lars V. Schäfer and Gert Bange and Martin Thanbichler},
journal = {Molecular Cell},
year = {2026},
month = oct,
doi = {10.1016/j.molcel.2021.09.004},
url = {https://hal.science/hal-05780521v1},
note = {CC BY},
}
RIS
TY - JOUR
TI - The CTPase activity of ParB determines the size and dynamics of prokaryotic DNA partition complexes
AU - Manuel Osorio-Valeriano
AU - Florian Altegoer
AU - Chandan K. Das
AU - Wieland Steinchen
AU - Gaël Panis
AU - Lara Connolley
AU - Giacomo Giacomelli
AU - Helge Feddersen
AU - Laura Corrales-Guerrero
AU - Pietro I. Giammarinaro
AU - Juri Hanßmann
AU - Marc Bramkamp
AU - Patrick H. Viollier
AU - Seán Murray
AU - Lars V. Schäfer
AU - Gert Bange
AU - Martin Thanbichler
PY - 2026
DA - 2026/10/06
JO - Molecular Cell
DO - 10.1016/j.molcel.2021.09.004
UR - https://hal.science/hal-05780521v1
AB - ParB-like CTPases mediate the segregation of bacterial chromosomes and low-copy number plasmids. They act as DNA-sliding clamps that are loaded at parS motifs in the centromere of target DNA molecules and spread laterally to form large nucleoprotein complexes serving as docking points for the DNA segregation machinery. Here, we solve crystal structures of ParB in the pre- and post-hydrolysis state and illuminate the catalytic mechanism of nucleotide hydrolysis. Moreover, we identify conformational changes that underlie the CTP- and parS-dependent closure of ParB clamps. The study of CTPase-deficient ParB variants reveals that CTP hydrolysis serves to limit the sliding time of ParB clamps and thus drives the establishment of a well-defined ParB diffusion gradient across the centromere whose dynamics are critical for DNA segregation. These findings clarify the role of the ParB CTPase cycle in partition complex assembly and function and thus advance our understanding of this prototypic CTP-dependent molecular switch.
SN - 1097-2765
SN - 1097-4164
ER -