TY - JOUR TI - Distinct architectural requirements for the parS centromeric sequence of the pSM19035 plasmid partition machinery AU - Volante, Andrea AU - Alonso, Juan Carlos AU - Mizuuchi, Kiyoshi A2 - Xiao, Jie A2 - Akhmanova, Anna VL - 11 PY - 2022 DA - 2022/09/05 SP - e79480 C1 - eLife 2022;11:e79480 DO - 10.7554/eLife.79480 UR - https://doi.org/10.7554/eLife.79480 AB - Three-component ParABS partition systems ensure stable inheritance of many bacterial chromosomes and low-copy-number plasmids. ParA localizes to the nucleoid through its ATP-dependent nonspecific DNA-binding activity, whereas centromere-like parS-DNA and ParB form partition complexes that activate ParA-ATPase to drive the system dynamics. The essential parS sequence arrangements vary among ParABS systems, reflecting the architectural diversity of their partition complexes. Here, we focus on the pSM19035 plasmid partition system that uses a ParBpSM of the ribbon-helix-helix (RHH) family. We show that parSpSM with four or more contiguous ParBpSM-binding sequence repeats is required to assemble a stable ParApSM-ParBpSM complex and efficiently activate the ParApSM-ATPase, stimulating complex disassembly. Disruption of the contiguity of the parSpSM sequence array destabilizes the ParApSM-ParBpSM complex and prevents efficient ATPase activation. Our findings reveal the unique architecture of the pSM19035 partition complex and how it interacts with nucleoid-bound ParApSM-ATP. KW - plasmid partition KW - ParABS system KW - chromosome segregation JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -