title: The evidence of large-scale DNA-induced compaction in the mycobacterial chromosomal ParB.
abstract: The bacterial chromosome trafficking apparatus or the segrosome participates in the mitotic-like segregation of the chromosomes prior to cell division in several bacteria. ParB, which is the parS DNA-binding component of the segrosome, polymerizes on the parS-adjacent chromosome to form a nucleoprotein filament of unknown nature for the segregation function. We combined static light scattering, circular dichroism and small-angle X-ray scattering to present evidence that the apo form of the mycobacterial ParB forms an elongated dimer with intrinsically disordered regions as well as folded domains in solution. A comparison of the solution scattering of the apo and the parS-bound ParBs indicates a rather drastic compaction of the protein upon DNA binding. We propose that this binding-induced conformational transition is priming the ParB for polymerization on the DNA template.
authors.affiliation: Hauptman Woodward Institute, Buffalo, NY 14203, USA. bchaudhuri@hwi.buffalo.edu
authors.forename: Barnali N
authors.initials: BN
authors.lastname: Chaudhuri
authors.forename: Rebecca
authors.initials: R
authors.lastname: Dean
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics*; D020090:Chromosome Segregation; D002876:Chromosomes, Bacterial / Q000235:genetics*; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics*; D008958:Models, Molecular; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D011487:Protein Conformation; D055503:Protein Multimerization
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial