1VZ0

Chromosome segregation protein Spo0J from Thermus thermophilus

Summary for 1VZ0

• Entry DOI: 10.2210/pdb1vz0/pdb
• Descriptor: Chromosome-partitioning protein Spo0J, COBALT (II) ION, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: nuclear protein, chromosome segregation, dna-binding, helix-turn-helix
• Biological source: Thermus thermophilus HB27
• Total number of polymer chains: 8
• Total formula weight: 205226.54

Authors

Leonard, T.A.,Butler, P.J.G.,Lowe, J. (deposition date: 2004-05-12, release date: 2004-07-19, Last modification date: 2024-05-08)

Primary citation

Leonard, T.A.,Butler, P.J.,Lowe, J.
Structural analysis of the chromosome segregation protein Spo0J from Thermus thermophilus.
Mol. Microbiol., 53:419-432, 2004

PubMed Abstract: Prokaryotic chromosomes and plasmids encode partitioning systems that are required for DNA segregation at cell division. The plasmid partitioning loci encode two proteins, ParA and ParB, and a cis-acting centromere-like site denoted parS. The chromosomally encoded homologues of ParA and ParB, Soj and Spo0J, play an active role in chromosome segregation during bacterial cell division and sporulation. Spo0J is a DNA-binding protein that binds to parS sites in vivo. We have solved the X-ray crystal structure of a C-terminally truncated Spo0J (amino acids 1-222) from Thermus thermophilus to 2.3 A resolution by multiwavelength anomalous dispersion. It is a DNA-binding protein with structural similarity to the helix-turn-helix (HTH) motif of the lambda repressor DNA-binding domain. The crystal structure is an antiparallel dimer with the recognition alpha-helices of the HTH motifs of each monomer separated by a distance of 34 A corresponding to the length of the helical repeat of B-DNA. Sedimentation velocity and equilibrium ultracentrifugation studies show that full-length Spo0J exists in a monomer-dimer equilibrium in solution and that Spo0J1-222 is exclusively monomeric. Sedimentation of the C-terminal domain of Spo0J shows it to be exclusively dimeric, confirming that the C-terminus is the primary dimerization domain. We hypothesize that the C-terminus mediates dimerization of Spo0J, thereby effectively increasing the local concentration of the N-termini, which most probably dimerize, as shown by our structure, upon binding to a cognate parS site.

PubMed: 15228524
DOI: 10.1111/j.1365-2958.2004.04133.x

Experimental method

X-RAY DIFFRACTION (2.3 Å)