TY - JOUR TI - CTP and parS coordinate ParB partition complex dynamics and ParA-ATPase activation for ParABS-mediated DNA partitioning AU - Taylor, James A AU - Seol, Yeonee AU - Budhathoki, Jagat AU - Neuman, Keir C AU - Mizuuchi, Kiyoshi A2 - Surrey, Thomas A2 - Dötsch, Volker A2 - Gruber, Stephan VL - 10 PY - 2021 DA - 2021/07/21 SP - e65651 C1 - eLife 2021;10:e65651 DO - 10.7554/eLife.65651 UR - https://doi.org/10.7554/eLife.65651 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. KW - plasmid partition KW - chromosome segregation KW - CTPase KW - ParB spreading KW - diffusion-ratchet KW - magnetic tweezers JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -