Condensin Smc2-Smc4 Dimers Are Flexible and Dynamic

Jorine M Eeftens; Allard J Katan; Marc Kschonsak; Markus Hassler; Liza de Wilde; Essam M Dief; Christian H Haering; Cees Dekker

doi:10.1016/j.celrep.2016.01.063

Condensin Smc2-Smc4 Dimers Are Flexible and Dynamic

Cell Rep. 2016 Mar 1;14(8):1813-8. doi: 10.1016/j.celrep.2016.01.063. Epub 2016 Feb 18.

Authors

Jorine M Eeftens¹, Allard J Katan¹, Marc Kschonsak², Markus Hassler², Liza de Wilde¹, Essam M Dief¹, Christian H Haering³, Cees Dekker⁴

Affiliations

¹ Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft 2628 CJ, the Netherlands.
² Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
³ Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany. Electronic address: christian.haering@embl.de.
⁴ Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft 2628 CJ, the Netherlands. Electronic address: c.dekker@tudelft.nl.

Abstract

Structural maintenance of chromosomes (SMC) protein complexes, including cohesin and condensin, play key roles in the regulation of higher-order chromosome organization. Even though SMC proteins are thought to mechanistically determine the function of the complexes, their native conformations and dynamics have remained unclear. Here, we probe the topology of Smc2-Smc4 dimers of the S. cerevisiae condensin complex with high-speed atomic force microscopy (AFM) in liquid. We show that the Smc2-Smc4 coiled coils are highly flexible polymers with a persistence length of only ∼ 4 nm. Moreover, we demonstrate that the SMC dimers can adopt various architectures that interconvert dynamically over time, and we find that the SMC head domains engage not only with each other, but also with the hinge domain situated at the other end of the ∼ 45-nm-long coiled coil. Our findings reveal structural properties that provide insights into the molecular mechanics of condensin complexes.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Carrier Proteins / chemistry*
Carrier Proteins / genetics
Carrier Proteins / metabolism
Cell Cycle Proteins
Chromosomal Proteins, Non-Histone / chemistry*
Chromosomal Proteins, Non-Histone / genetics
Chromosomal Proteins, Non-Histone / metabolism
Chromosomes, Fungal / chemistry*
Chromosomes, Fungal / ultrastructure
Gene Expression
Image Processing, Computer-Assisted
Microscopy, Atomic Force / methods
Molecular Dynamics Simulation
Molecular Imaging
Monte Carlo Method
Nuclear Proteins / chemistry*
Nuclear Proteins / genetics
Nuclear Proteins / metabolism
Protein Domains
Protein Multimerization*
Protein Structure, Tertiary
Saccharomyces cerevisiae / genetics*
Saccharomyces cerevisiae / metabolism
Saccharomyces cerevisiae / ultrastructure
Saccharomyces cerevisiae Proteins / chemistry*
Saccharomyces cerevisiae Proteins / genetics
Saccharomyces cerevisiae Proteins / metabolism

Substances

Carrier Proteins
Cell Cycle Proteins
Chromosomal Proteins, Non-Histone
Nuclear Proteins
SMC2 protein, S cerevisiae
SMC4 protein, S cerevisiae
Saccharomyces cerevisiae Proteins