8x19

From Proteopedia

Structure of nucleosome-bound SRCAP-C in the ADP-BeFx-bound state

Structural highlights

8x19 is a 18 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Electron Microscopy, Resolution 3.2Å
Ligands:	, , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

H2A1C_HUMAN Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling.

Publication Abstract from PubMed

Histone variant H2A.Z is found at promoters and regulates transcription. The ATP-dependent chromatin remodeler SRCAP complex (SRCAP-C) promotes the replacement of canonical histone H2A-H2B dimer with H2A.Z-H2B dimer. Here, we determined structures of human SRCAP-C bound to H2A-containing nucleosome at near-atomic resolution. The SRCAP subunit integrates a 6-subunit actin-related protein (ARP) module and an ATPase-containing motor module. The ATPase-associated ARP module encircles half of the nucleosome along the DNA and may restrain net DNA translocation, a unique feature of SRCAP-C. The motor module adopts distinct nucleosome binding modes in the apo (nucleotide-free), ADP-bound, and ADP-BeF(x)-bound states, suggesting that ATPase-driven movement destabilizes H2A-H2B by unwrapping the entry DNA and pulls H2A-H2B out of nucleosome through the ZNHIT1 subunit. Structure-guided chromatin immunoprecipitation sequencing analysis confirmed the requirement of H2A-contacting ZNHIT1 in maintaining H2A.Z occupancy on the genome. Our study provides structural insights into the mechanism of H2A-H2A.Z exchange mediated by SRCAP-C.

Structural insights into histone exchange by human SRCAP complex.,Yu J, Sui F, Gu F, Li W, Yu Z, Wang Q, He S, Wang L, Xu Y Cell Discov. 2024 Feb 8;10(1):15. doi: 10.1038/s41421-023-00640-1. PMID:38331872^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Yu J, Sui F, Gu F, Li W, Yu Z, Wang Q, He S, Wang L, Xu Y. Structural insights into histone exchange by human SRCAP complex. Cell Discov. 2024 Feb 8;10(1):15. PMID:38331872 doi:10.1038/s41421-023-00640-1