2NTZ

Structure of a ParB-DNA complex reveals a double B-box interaction

Summary for 2NTZ

• Entry DOI: 10.2210/pdb2ntz/pdb
• Related: 1ZX4
• Descriptor: 5'-D(*CP*GP*TP*GP*AP*AP*AP*TP*CP*GP*CP*CP*AP*CP*GP*A)-3', 5'-D(*TP*CP*GP*TP*GP*GP*CP*GP*AP*TP*TP*TP*CP*AP*CP*G)-3', ParB (3 entities in total)
• Functional Keywords: partition, segregation, parb, para, cell cycle-dna complex, cell cycle/dna
• Biological source: Enterobacteria phage P1
• Total number of polymer chains: 6
• Total formula weight: 64049.93

Authors

Schumacher, M.A.,Mansoor, A.,Funnell, B.E. (deposition date: 2006-11-08, release date: 2007-02-20, Last modification date: 2024-10-30)

Primary citation

Schumacher, M.A.,Mansoor, A.,Funnell, B.E.
Structure of a four-way bridged ParB-DNA complex provides insight into P1 segrosome assembly.
J.Biol.Chem., 282:10456-10464, 2007

PubMed Abstract: The plasmid partition process is essential for plasmid propagation and is mediated by par systems, consisting of centromere-like sites and two proteins, ParA and ParB. In the first step of partition by the archetypical P1 system, ParB binds a complicated centromere-like site to form a large nucleoprotein segrosome. ParB is a dimeric DNA-binding protein that can bridge between both A-boxes and B-boxes located on the centromere. Its helix-turn-helix domains bind A-boxes and the dimer domain binds B-boxes. Binding of the first ParB dimer nucleates the remaining ParB molecules onto the centromere site, which somehow leads to the formation of a condensed segrosome superstructure. To further understand this unique DNA spreading capability of ParB, we crystallized and determined the structure of a 1:2 ParB-(142-333):A3-B2-box complex to 3.35A resolution. The structure reveals a remarkable four-way, protein-DNA bridged complex in which both ParB helix-turn-helix domains simultaneously bind adjacent A-boxes and the dimer domain bridges between two B-boxes. The multibridging capability and the novel dimer domain-B-box interaction, which juxtaposes the DNA sites close in space, suggests a mechanism for the formation of the wrapped solenoid-like segrosome superstructure. This multibridging capability of ParB is likely critical in its partition complex formation and pairing functions.

PubMed: 17293348
DOI: 10.1074/jbc.M610603200

Experimental method

X-RAY DIFFRACTION (3.35 Å)