RT Journal Article
SR Electronic
T1 CTP and <em>parS</em> coordinate ParB partition complex dynamics and ParA-ATPase activation for ParABS-mediated DNA partitioning
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.01.24.427996
DO 10.1101/2021.01.24.427996
A1 James A. Taylor
A1 Yeonee Seol
A1 Jagat Budhathoki
A1 Keir C. Neuman
A1 Kiyoshi Mizuuchi
YR 2021
UL http://biorxiv.org/content/early/2021/07/10/2021.01.24.427996.abstract
AB ParABS partition systems, comprising the centromere-like DNA sequence parS, the parS-binding ParB-CTPase and the nucleoid-binding ParA-ATPase, ensure faithful segregation of bacterial chromosomes and low-copy-number plasmids. F-plasmid partition complexes containing ParBF and parSF move by generating and following a local concentration gradient of nucleoid-bound ParAF. However, the process through which ParBF activates ParAF-ATPase has not been defined. We studied CTP- and parSF-modulated ParAF—ParBF complex assembly, in which DNA-bound ParAF-ATP dimers are activated for ATP hydrolysis by interacting with two ParBF N-terminal domains. CTP or parSF enhances the ATPase rate without significantly accelerating ParAF—ParBF complex assembly. Together, parSF and CTP accelerate ParAF—ParBF assembly without further significant increase in ATPase rate. Magnetic-tweezers experiments showed that CTP promotes multiple ParBF loading onto parSF-containing DNA, generating condensed partition complex-like assemblies. We propose that ParBF in the partition complex adopts a conformation that enhances ParBF—ParBF and ParAF—ParBF interactions promoting efficient partitioning.Competing Interest StatementThe authors have declared no competing interest.