Premium
Structural analysis of the ParR/ parC plasmid partition complex
Author(s) -
MøllerJensen Jakob,
Ringgaard Simon,
Mercogliano Christopher P,
Gerdes Kenn,
Löwe Jan
Publication year - 2007
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601864
Subject(s) - biology , plasmid , computational biology , genetics , gene
Accurate DNA partition at cell division is vital to all living organisms. In bacteria, this process can involve partition loci, which are found on both chromosomes and plasmids. The initial step in Escherichia coli plasmid R1 partition involves the formation of a partition complex between the DNA‐binding protein ParR and its cognate centromere site parC on the DNA. The partition complex is recognized by a second partition protein, the actin‐like ATPase ParM, which forms filaments required for the active bidirectional movement of DNA replicates. Here, we present the 2.8 Å crystal structure of ParR from E. coli plasmid pB171. ParR forms a tight dimer resembling a large family of dimeric ribbon–helix–helix (RHH) 2 site‐specific DNA‐binding proteins. Crystallographic and electron microscopic data further indicate that ParR dimers assemble into a helix structure with DNA‐binding sites facing outward. Genetic and biochemical experiments support a structural arrangement in which the centromere‐like parC DNA is wrapped around a ParR protein scaffold. This structure holds implications for how ParM polymerization drives active DNA transport during plasmid partition.