title: SMC condensin entraps chromosomal DNA by an ATP hydrolysis dependent loading mechanism in Bacillus subtilis.
abstract: Smc-ScpAB forms elongated, annular structures that promote chromosome segregation, presumably by compacting and resolving sister DNA molecules. The mechanistic basis for its action, however, is only poorly understood. Here, we have established a physical assay to determine whether the binding of condensin to native chromosomes in Bacillus subtilis involves entrapment of DNA by the Smc-ScpAB ring. To do so, we have chemically cross-linked the three ring interfaces in Smc-ScpAB and thereafter isolated intact chromosomes under protein denaturing conditions. Exclusively species of Smc-ScpA, which were previously cross-linked into covalent rings, remained associated with chromosomal DNA. DNA entrapment is abolished by mutations that interfere with the Smc ATPase cycle and strongly reduced when the recruitment factor ParB is deleted, implying that most Smc-ScpAB is loaded onto the chromosome at parS sites near the replication origin. We furthermore report a physical interaction between native Smc-ScpAB and chromosomal DNA fragments.
authors.affiliation: Chromosome Organization and Dynamics, Max Planck Institute of Biochemistry, Martinsried, Germany.
authors.forename: Larissa
authors.initials: L
authors.lastname: Wilhelm
authors.affiliation: Chromosome Organization and Dynamics, Max Planck Institute of Biochemistry, Martinsried, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Bürmann
authors.affiliation: Chromosome Organization and Dynamics, Max Planck Institute of Biochemistry, Martinsried, Germany.
authors.forename: Anita
authors.initials: A
authors.lastname: Minnen
authors.affiliation: Department of Biological Sciences, KAIST Institute for the Biocentury, Cancer Metastasis Control Center, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
authors.forename: Ho-Chul
authors.initials: HC
authors.lastname: Shin
authors.affiliation: Chromosome Organization and Dynamics, Max Planck Institute of Biochemistry, Martinsried, Germany.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Toseland
authors.affiliation: Department of Biological Sciences, KAIST Institute for the Biocentury, Cancer Metastasis Control Center, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
authors.forename: Byung-Ha
authors.initials: BH
authors.lastname: Oh
authors.affiliation: Chromosome Organization and Dynamics, Max Planck Institute of Biochemistry, Martinsried, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Gruber
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D001412:Bacillus subtilis; D001426:Bacterial Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002876:Chromosomes, Bacterial / Q000235:genetics*; D004269:DNA, Bacterial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006868:Hydrolysis; D046912:Multiprotein Complexes / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D018797:Cell Cycle Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; C118650:SMC protein, Bacteria; C108312:condensin complexes; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases
keywords: B. subtilis; ParB protein; Smc proteins; biochemistry; chromosome condensation; chromosome segregation; chromosomes; condensin; genes; sliding clamp