PT  - JOURNAL ARTICLE
AU  - Gemma L. M. Fisher
AU  - César L. Pastrana
AU  - Victoria A. Higman
AU  - Alan Koh
AU  - James A. Taylor
AU  - Annika Butterer
AU  - Timothy D. Craggs
AU  - Frank Sobott
AU  - Heath Murray
AU  - Matthew P. Crump
AU  - Fernando Moreno-Herrero
AU  - Mark S. Dillingham
TI  - The C-terminal domain of ParB is critical for dynamic DNA binding and bridging interactions which condense the bacterial centromere
AID  - 10.1101/122986
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 122986
4099  - http://biorxiv.org/content/early/2017/04/01/122986.short
4100  - http://biorxiv.org/content/early/2017/04/01/122986.full
AB  - The ParB protein forms DNA bridging interactions around parS to form networks which condense DNA and earmark the bacterial chromosome for segregation. The mechanism underlying the formation of ParB nucleoprotein complexes is unclear. We show here that the central DNA binding domain is essential for anchoring at parS, and that this interaction is not required for DNA condensation. Structural analysis of the C-terminal domain reveals a dimer with a lysine-rich surface that binds DNA non-specifically and is essential for DNA condensation in vitro. Mutation of either the dimerisation or the DNA binding interface eliminates ParB foci formation in vivo. Moreover, the free C-terminal domain can rapidly decondense ParB networks independently of its ability to bind DNA. Our work reveals a dual role for the C-terminal domain of ParB as both a DNA binding and bridging interface, and highlights the dynamic nature of ParB networks.