Abstract
Condensin is a conserved SMC complex that uses its ATPase machinery to structure genomes, but how it does so is largely unknown. We show that condensin's ATPase has a dual role in chromosome condensation. Mutation of one ATPase site impairs condensation, while mutating the second site results in hyperactive condensin that compacts DNA faster than wild-type, both in vivo and in vitro. Whereas one site drives loop formation, the second site is involved in the formation of more stable higher-order Z loop structures. Using hyperactive condensin I, we reveal that condensin II is not intrinsically needed for the shortening of mitotic chromosomes. Condensin II rather is required for a straight chromosomal axis and enables faithful chromosome segregation by counteracting the formation of ultrafine DNA bridges. SMC complexes with distinct roles for each ATPase site likely reflect a universal principle that enables these molecular machines to intricately control chromosome architecture.
Original language | English |
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Pages (from-to) | 724-737.e5 |
Journal | Molecular Cell |
Volume | 76 |
Issue number | 5 |
DOIs | |
Publication status | Published - 2019 |
Keywords
- ABC ATPase
- chromosome condensation
- cohesin
- condensin
- DNA loop extrusion
- SMC complexes