Seven of the proteins (Arp7, Arp9, Rsc6, Rsc8, Sfh1, Sth1 and Rsc9) are conserved in all eukaryotic SWI/SNF chromatin remodeling complexes, with Sth1 containing the ATPase domain that is responsible for the remodeling activity ( Cairns et al., 1996 Saha et al., 2002). RSC has a molecular weight of ~1.1 MDa and is composed of 17 proteins, with two copies of Rsc8 and one copy of either Rsc1 or Rsc2 ( Cairns et al., 1996 Cairns et al., 1999). Additionally, RSC is also involved in many transcription-independent processes, such as mitotic division, double stranded break repair, and telomere maintenance ( Krietenstein et al., 2016 Erkina et al., 2010 Kuryan et al., 2012 Campsteijn et al., 2007 Shim et al., 2007 Ungar et al., 2009 Ng et al., 2002).
Rsc manuscript central free#
In the context of transcription, RSC is responsible for maintaining nucleosome free regions (NFR), while SWI/SNF plays a role in remodeling nucleosomes during transcription initiation ( Nagai et al., 2017 Krietenstein et al., 2016 Klein-Brill et al., 2019).
RSC is essential for yeast viability and is ten times more abundant than SWI/SNF ( Cairns et al., 1996). SWI/SNF chromatin remodelers reposition nucleosomes by translocating DNA around the histone octamer, and in vitro assays have shown that they move nucleosomes to the ends of linear DNA fragments before evicting the histones from the DNA ( Clapier et al., 2016). cerevisiae there are two members of the SWI/SNF family of chromatin remodelers: RSC and SWI/SNF ( Côté et al., 1994 Cairns et al., 1996). Together, these remodelers give rise to the distinct chromatin landscapes observed in eukaryotic cells and determine how genetic information is organized, replicated, transcribed, and repaired ( Yen et al., 2012). Each of these remodelers plays distinct roles based on how they select and affect target nucleosomes. Our findings provide structural insights into the conserved assembly process for all members of the SWI/SNF family of remodelers, and illustrate how RSC selects, engages, and remodels nucleosomes.Įukaryotes have four major families of chromatin remodelers: SWI/SNF, ISWI, CHD, and INO80 ( Clapier and Cairns, 2009). Our cryo-EM analysis of RSC bound to a nucleosome core particle shows that in addition to the expected nucleosome-Sth1 interactions, RSC engages histones and nucleosomal DNA through one arm of the core structure, composed of the Rsc8 SWIRM domains, Sfh1 and Npl6. The flexible ATPase lobe, composed of helicase subunit Sth1, Arp7, Arp9 and Rtt102, is anchored to this core by the N-terminus of Sth1. The core structure is scaffolded by an asymmetric Rsc8 dimer and built with the evolutionarily conserved subunits Sfh1, Rsc6, Rsc9 and Sth1. Here, we report cryo-electron microscopy (cryo-EM) and crosslinking mass spectrometry (CLMS) studies of yeast RSC complex and show that RSC is composed of a rigid tripartite core and two flexible lobes. The Saccharomyces cerevisiae RSC ( Remodeling the Structure of Chromatin) complex, a member of the SWI/SNF chromatin remodeler family, plays critical roles in genome maintenance, transcription, and DNA repair. 6V92Įukaryotic DNA is packaged into nucleosome arrays, which are repositioned by chromatin remodeling complexes to control DNA accessibility. Patel AB, Moore CM, Greber BJ, Nogales E.
The cryo-EM maps and coordinate models have been deposited in the Electron Microscopy Data Bank with the accession codes EMD-21107 (RSC core), EMD-21105 (head lobe multibody), EMD-21103 (body lobe multibody), EMD-21098 (arm lobe multibody), EMD-21106 (head lobe classified), EMD-21102 (body lobe classified), EMD-21104 (arm lobe classified), EMD-21114 (RSC-NCP locked) and EMD-21110 (RSC-NCP swiveled) and in the Protein Data Bank with the accession codes PDB-6V8O (RSC core) and PDB-6V92 (RSC-NCP). Patel AB, Moore CM, Greber BJ, Nogales E.
0 kommentar(er)
