RT Journal Article
SR Electronic
T1 The CTPase activity of ParB acts as a timing mechanism to control the dynamics and function of prokaryotic DNA partition complexes
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.05.05.442810
DO 10.1101/2021.05.05.442810
A1 Manuel Osorio-Valeriano
A1 Florian Altegoer
A1 Chandan K. Das
A1 Wieland Steinchen
A1 Gaël Panis
A1 Lara Connolley
A1 Giacomo Giacomelli
A1 Helge Feddersen
A1 Laura Corrales-Guerrero
A1 Pietro Giammarinaro
A1 Juri Hanßmann
A1 Marc Bramkamp
A1 Patrick H. Viollier
A1 Seán Murray
A1 Lars V. Schäfer
A1 Gert Bange
A1 Martin Thanbichler
YR 2021
UL http://biorxiv.org/content/early/2021/05/05/2021.05.05.442810.abstract
AB DNA partitioning CTPases of the ParB family 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 centromeric region of target DNA molecules and then spread laterally to form large nucleoprotein complexes that serve as docking points for the DNA segregation machinery. Here, we identify conformational changes that underlie the CTP- and parS-dependent closure of ParB clamps. Moreover, we solve crystal structures of ParB in the pre- and post-hydrolysis state and provide insights into the catalytic mechanism underlying nucleotide hydrolysis. The characterization of CTPase-deficient ParB variants reveals that CTP hydrolysis serves as a timing mechanism to control the sliding time of ParB. Hyperstable clamps are trapped on the DNA, leading to excessing spreading and severe chromosome segregation defects in vivo. These findings clarify the role of the ParB CTPase cycle in partition complex dynamics and function and thus complete our understanding of this prototypic CTP-dependent molecular switch.Competing Interest StatementThe authors have declared no competing interest.