Reconstitution and subunit geometry of human condensin complexes
| Autor: | Itay Onn, Nobuki Aono, Tatsuya Hirano, Michiko Hirano |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
Cell Extracts
Models Molecular Protein Conformation Protein subunit Condensin Xenopus Molecular Sequence Data Mitosis Geometry Cell Cycle Proteins macromolecular substances General Biochemistry Genetics and Molecular Biology Article Chromosome segregation Condensin complex Protein structure Chromosome Segregation Animals Humans Amino Acid Sequence Molecular Biology Ovum Adenosine Triphosphatases General Immunology and Microbiology Cohesin biology General Neuroscience SMC protein Genetic Complementation Test Nuclear Proteins DNA-Binding Proteins Protein Subunits Multiprotein Complexes biology.protein Carrier Proteins |
| Popis: | Vertebrate cells possess two different condensin complexes, known as condensin I and condensin II, that play a fundamental role in chromosome assembly and segregation during mitosis. Each complex contains a pair of structural maintenance of chromosomes (SMC) ATPases, a kleisin subunit and two HEAT-repeat subunits. Here we use recombinant human condensin subunits to determine their geometry within each complex. We show that both condensin I and condensin II have a pseudo-symmetrical structure, in which the N-terminal half of kleisin links the first HEAT subunit to SMC2, whereas its C-terminal half links the second HEAT subunit to SMC4. No direct interactions are detectable between the SMC dimer and the HEAT subunits, indicating that the kleisin subunit acts as the linchpin in holocomplex assembly. ATP has little, if any, effects on the assembly and integrity of condensin. Cleavage pattern of SMC2 by limited proteolysis is changed upon its binding to ATP or DNA. Our results shed new light on the architecture and dynamics of this highly elaborate machinery designed for chromosome assembly. |
| Databáze: | OpenAIRE |
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