DNA-loop extruding condensin complexes can traverse one another

DNA-loop extruding condensin complexes can traverse one another

Kim, E. (TU Delft BN/Cees Dekker Lab; Kavli institute of nanoscience Delft)
Kerssemakers, J.W.J. (TU Delft BN/Technici en Analisten; Kavli institute of nanoscience Delft)
Shaltiel, Indra A. (European Molecular Biology Laboratory Heidelberg)
Haering, Christian H. (European Molecular Biology Laboratory Heidelberg)
Dekker, C. (TU Delft BN/Cees Dekker Lab; Kavli institute of nanoscience Delft)

2020

Condensin, a key component of the structure maintenance of chromosome (SMC) protein complexes, has recently been shown to be a motor that extrudes loops of DNA¹. It remains unclear, however, how condensin complexes work together to collectively package DNA into chromosomes. Here we use time-lapse single-molecule visualization to study mutual interactions between two DNA-loop-extruding yeast condensins. We find that these motor proteins, which, individually, extrude DNA in one direction only are able to dynamically change each other’s DNA loop sizes, even when far apart. When they are in close proximity, condensin complexes are able to traverse each other and form a loop structure, which we term a Z-loop—three double-stranded DNA helices aligned in parallel with one condensin at each edge. Z-loops can fill gaps left by single loops and can form symmetric dimer motors that pull in DNA from both sides. These findings indicate that condensin may achieve chromosomal compaction using a variety of looping structures.

http://resolver.tudelft.nl/uuid:bd246369-2a6d-4c90-a297-d3789f66a319

https://doi.org/10.1038/s41586-020-2067-5

2020-09-04

0028-0836

Nature: international weekly journal of science, 579 (7799), 438-442

Accepted Author Manuscript

Institutional Repository

journal article

© 2020 E. Kim, J.W.J. Kerssemakers, Indra A. Shaltiel, Christian H. Haering, C. Dekker