1vz0
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CHROMOSOME SEGREGATION PROTEIN SPO0J FROM THERMUS THERMOPHILUS
OverviewOverview
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.
About this StructureAbout this Structure
1VZ0 is a Single protein structure of sequence from Thermus thermophilus with CO and MG as ligands. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
ReferenceReference
Structural analysis of the chromosome segregation protein Spo0J from Thermus thermophilus., Leonard TA, Butler PJ, Lowe J, Mol Microbiol. 2004 Jul;53(2):419-32. PMID:15228524
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