3NO7

Crystal structure of the centromere-binding protein ParB from plasmid pCXC100

3NO7 の概要

• エントリーDOI: 10.2210/pdb3no7/pdb
• 分子名称: Putative plasmid related protein, SULFATE ION (3 entities in total)
• 機能のキーワード: ribbon-helix-helix, dna binding protein
• 由来する生物種: Leifsonia xyli subsp. cynodontis (Clavibacter xyli cynodontis)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 18998.69

構造登録者

Ye, K. (登録日: 2010-06-24, 公開日: 2010-12-22, 最終更新日: 2023-12-27)

主引用文献

Huang, L.,Yin, P.,Zhu, X.,Zhang, Y.,Ye, K.
Crystal structure and centromere binding of the plasmid segregation protein ParB from pCXC100
Nucleic Acids Res., 39:2954-2968, 2011

PubMed Abstract: Plasmid pCXC100 from the Gram-positive bacterium Leifsonia xyli subsp. cynodontis uses a type Ib partition system that includes a centromere region, a Walker-type ATPase ParA and a centromere-binding protein ParB for stable segregation. However, ParB shows no detectable sequence homology to any DNA-binding motif. Here, we study the ParB centromere interaction by structural and biochemical approaches. The crystal structure of the C-terminal DNA-binding domain of ParB at 1.4 Å resolution reveals a dimeric ribbon-helix-helix (RHH) motif, supporting the prevalence of RHH motif in centromere binding. Using hydroxyl radical footprinting and quantitative binding assays, we show that the centromere core comprises nine uninterrupted 9-nt direct repeats that can be successively bound by ParB dimers in a cooperative manner. However, the interaction of ParB with a single subsite requires 18 base pairs covering one immediate repeat as well as two halves of flanking repeats. Through mutagenesis, sequence specificity was determined for each position of an 18-bp subsite. These data suggest an unique centromere recognition mechanism by which the repeat sequence is jointly specified by adjacent ParB dimers bound to an overlapped region.

PubMed: 21123191
DOI: 10.1093/nar/gkq915

実験手法

X-RAY DIFFRACTION (1.4 Å)