The interplay between asymmetric and symmetric DNA loop extrusion.
The interplay between asymmetric and symmetric DNA loop extrusion.
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DOI：
10.7554/elife.63528
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发表时间：
2020-12-09
期刊：
影响因子：
7.7
通讯作者：
Mirny LA
中科院分区：
文献类型：
--
作者：
Banigan EJ;Mirny LA
Chromosome compaction is essential for reliable transmission of genetic information. Experiments suggest that ∼1000-fold compaction is driven by condensin complexes that extrude chromatin loops, by progressively collecting chromatin fiber from one or both sides of the complex to form a growing loop. Theory indicates that symmetric two-sided loop extrusion can achieve such compaction, but recent single-molecule studies (Golfier et al., 2020) observed diverse dynamics of condensins that perform one-sided, symmetric two-sided, and asymmetric two-sided extrusion. We use simulations and theory to determine how these molecular properties lead to chromosome compaction. High compaction can be achieved if even a small fraction of condensins have two essential properties: a long residence time and the ability to perform two-sided (not necessarily symmetric) extrusion. In mixtures of condensins I and II, coupling two-sided extrusion and stable chromatin binding by condensin II promotes compaction. These results provide missing connections between single-molecule observations and chromosome-scale organization.
