2Q2K

Structure of nucleic-acid binding protein

Summary for 2Q2K

• Entry DOI: 10.2210/pdb2q2k/pdb
• Descriptor: DNA (5'-D(*AP*GP*TP*AP*TP*AP*(5IU)P*AP*CP*(5IU)P*AP*GP*TP*AP*TP*AP*TP*AP*CP*T)-3'), Hypothetical protein, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID (3 entities in total)
• Functional Keywords: protein-dna, partition, segregation, parb, dna binding protein-dna complex, dna binding protein/dna
• Biological source: Staphylococcus aureus
• Total number of polymer chains: 3
• Total formula weight: 22927.59

Authors

Schumacher, M.A.,Glover, T.,Firth, N. (deposition date: 2007-05-28, release date: 2008-02-05, Last modification date: 2024-02-21)

Primary citation

Schumacher, M.A.,Glover, T.C.,Brzoska, A.J.,Jensen, S.O.,Dunham, T.D.,Skurray, R.A.,Firth, N.
Segrosome structure revealed by a complex of ParR with centromere DNA.
Nature, 450:1268-1271, 2007

PubMed Abstract: The stable inheritance of genetic material depends on accurate DNA partition. Plasmids serve as tractable model systems to study DNA segregation because they require only a DNA centromere, a centromere-binding protein and a force-generating ATPase. The centromeres of partition (par) systems typically consist of a tandem arrangement of direct repeats. The best-characterized par system contains a centromere-binding protein called ParR and an ATPase called ParM. In the first step of segregation, multiple ParR proteins interact with the centromere repeats to form a large nucleoprotein complex of unknown structure called the segrosome, which binds ParM filaments. pSK41 ParR binds a centromere consisting of multiple 20-base-pair (bp) tandem repeats to mediate both transcription autoregulation and segregation. Here we report the structure of the pSK41 segrosome revealed in the crystal structure of a ParR-DNA complex. In the crystals, the 20-mer tandem repeats stack pseudo-continuously to generate the full-length centromere with the ribbon-helix-helix (RHH) fold of ParR binding successive DNA repeats as dimer-of-dimers. Remarkably, the dimer-of-dimers assemble in a continuous protein super-helical array, wrapping the DNA about its positive convex surface to form a large segrosome with an open, solenoid-shaped structure, suggesting a mechanism for ParM capture and subsequent plasmid segregation.

PubMed: 18097417
DOI: 10.1038/nature06392

Experimental method

X-RAY DIFFRACTION (3 Å)