Journal:Acta Cryst F:S2053230X24004655

Cryo-EM structure and functional analysis of chromatin remodeler RSF

Jiale Zhang, Heyu Zhao, Binqian Zou, Huadong Li, Shuqi Dong, Jiali Guan, Chi Wang, Weijie Li, Yutong Liu, Yingying Chen, Nadia Rasheed and Jun He ^[1]

Molecular Tour
RSF complex belongs to ISWI chromatin remodeling family and is composed of two subunits which are RSF1 (Remodeling and Spacing Factor 1) and SNF2h (Sucrose NonFermenting protein 2 Homolog). RSF complex participates in nucleosome spacing and assembly and then promotes nucleosome maturation. Though SNF2h has been studied extensively in the last few years, the remodeler RSF’s structural and functional properties still remain vague. Here, we report the cryoEM structure of RSF-nucleosome complex, the 3D model shows a two-lobe architecture of RSF, and the RSF-nucleosome (flanking with linker DNA) complex structure shows RSF complex moves the DNA away from the histone octamer surface at the DNA entry point. Additionally, nucleosome sliding assay and restriction enzyme accessibility assays (REAA) show that RSF1 subunit may bring changes in the SNF2h chromatin remodeling properties. As a “nucleosome ruler”，our RSF-dinucleosomes binding affinity test results propose that the critical distance RSF “measures” between two nucleosomes is about 24 bp.

Comparing 3D model of Class 0 of RSF-147 bp nucleosome complex (shown as white transparent surface) over 147 bp NCP structure (shown as ribbon; PDB:1eqz).

Comparing 3D model of Class 2 of RSF-147 bp nucleosome complex (shown as transparent surface) over 147 bp NCP structure (shown as ribbon; PDB:1eqz).

The extracted SNF2h subunit from the atomic model of the SNF2h-nucleosome complex (shown as ribbon; PDB: 8v4y) is fitted into the Cryo-EM map of Class 0 of RSF-38N38 NCP complex (shown as transparent surface).

References

1. ↑ doi: https://dx.doi.org/10.1107/S2053230X24004655