title: ATP-dependent positive supercoiling of DNA by 13S condensin: a biochemical implication for chromosome condensation.
abstract: 13S condensin is a five-subunit protein complex that plays a central role in mitotic chromosome condensation in Xenopus egg extracts. Two core subunits of this complex, XCAP-C and XCAP-E, belong to an emerging family of putative ATPases, the SMC family. We report here that 13S condensin has a DNA-stimulated ATPase activity and exhibits a high affinity for structured DNAs such as cruciform DNA. 13S condensin is able to introduce positive supercoils into a closed circular DNA in the presence of bacterial or eukaryotic topoisomerase I. The supercoiling reaction is ATP-dependent. We propose that 13S condensin wraps DNA in a right-handed direction by utilizing the energy of ATP hydrolysis. This reaction may represent a key mechanism underlying the compaction of chromatin fibers during mitosis.
authors.affiliation: Cold Spring Harbor Laboratory, New York 11724, USA.
authors.forename: K
authors.initials: K
authors.lastname: Kimura
authors.forename: T
authors.initials: T
authors.lastname: Hirano
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002843:Chromatin / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone; D002875:Chromosomes / Q000378:metabolism*; D004265:DNA Helicases; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D004270:DNA, Circular / Q000378:metabolism; D004278:DNA, Superhelical / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006868:Hydrolysis; D046912:Multiprotein Complexes; D009687:Nuclear Proteins / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D009865:Oocytes / Q000378:metabolism; D014981:Xenopus; D029867:Xenopus Proteins
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004270:DNA, Circular; D004278:DNA, Superhelical; D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; C109974:NCAPH protein, human; D009687:Nuclear Proteins; C490381:SMC2 protein, human; C090452:SMC4 protein, Xenopus; C090453:XCAP-E protein, Xenopus; D029867:Xenopus Proteins; C108312:condensin complexes; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; D004264:DNA Topoisomerases, Type I