7DLX

crystal structure of H2AM4>Z-H2B

Summary for 7DLX

• Entry DOI: 10.2210/pdb7dlx/pdb
• Descriptor: Histone H2B,Histone H2A (2 entities in total)
• Functional Keywords: histone, h2a mutant, h2a-h2b dimer, nuclear protein
• Biological source: Saccharomyces cerevisiae (strain RM11-1a) (Baker's yeast); More
• Total number of polymer chains: 8
• Total formula weight: 180270.78

Authors

Dai, L.C.,Zhou, Z. (deposition date: 2020-11-30, release date: 2021-06-16, Last modification date: 2023-11-29)

Primary citation

Dai, L.,Xiao, X.,Pan, L.,Shi, L.,Xu, N.,Zhang, Z.,Feng, X.,Ma, L.,Dou, S.,Wang, P.,Zhu, B.,Li, W.,Zhou, Z.
Recognition of the inherently unstable H2A nucleosome by Swc2 is a major determinant for unidirectional H2A.Z exchange.
Cell Rep, 35:109183-109183, 2021

PubMed Abstract: The multisubunit chromatin remodeler SWR1/SRCAP/p400 replaces the nucleosomal H2A-H2B dimer with the free-form H2A.Z-H2B dimer, but the mechanism governing the unidirectional H2A-to-H2A.Z exchange remains elusive. Here, we perform single-molecule force spectroscopy to dissect the disassembly/reassembly processes of the H2A nucleosome and H2A.Z nucleosome. We find that the N-terminal 1-135 residues of yeast SWR1 complex protein 2 (previously termed Swc2-Z) facilitate the disassembly of nucleosomes containing H2A but not H2A.Z. The Swc2-mediated nucleosome disassembly/reassembly requires the inherently unstable H2A nucleosome, whose instability is conferred by three H2A α2-helical residues, Gly47, Pro49, and Ile63, as they selectively weaken the structural rigidity of the H2A-H2B dimer. It also requires Swc2-ZN (residues 1-37) that directly anchors to the H2A nucleosome and functions in the SWR1-catalyzed H2A.Z replacement in vitro and yeast H2A.Z deposition in vivo. Our findings provide mechanistic insights into how the SWR1 complex discriminates between the H2A nucleosome and H2A.Z nucleosome, establishing a simple paradigm for the governance of unidirectional H2A.Z exchange.

PubMed: 34038732
DOI: 10.1016/j.celrep.2021.109183

Experimental method

X-RAY DIFFRACTION (2.395 Å)