Structure of the month - June 2004

Nat. Struct. Mol. Biol. Vol. 11, 2004, Pages 656-663

Crystal structure of ParB homolog KorB in complex with the operator DNA

Dheeraj Khare¹, Günter Ziegelin², Erich Lanka² and Udo Heinemann^1,3

^{1 Forschungsgruppe Kristallographie, Max-Delbrück-Centrum für Molekulare Medizin Berlin, Robert-Roessle-Str.10, 13125-Berlin, Germany
2 Max-Planck-Institut für Molekulare Genetik, Ihnestr. 73, D-14195 Berlin, Germany
3 Forschungsgruppe Kristallographie, Freie Universität Berlin, Takustr.6, 14195-Berlin, Germany}

Abstract

Species survival requires stringent control on how the genetic information is inherited to the offspring. Low-copy number genomes like bacterial chromosomes and certain plasmids have evolved partitioning (Par) mechanisms to ensure that daughter cells receive a full complement of the genetic material, which is in contrast to high-copy number plasmids that rely on random partitioning. All chromosomal or plasmid partitioning systems require three components, ParA a putative ATPase, ParB a sequence specific DNA binding protein and ParS a centromere like site. The KorB protein of broad host range plasmid RP4 plays a role in transcriptional regulation and also functions as a ParB homolog of plasmid's partitioning system. We have determined the X-ray structure of the DNA binding domain of KorB (KorB-O) in complex with a 17 bp DNA fragment containing the consensus OB sequence 5´-TTTAGC^G/_CGCTAAA-3´.