Molecular architecture of the ATP-dependent chromatin-remodeling complex SWR1.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 24034246.
- Also identified by DOI 10.1016/j.cell.2013.08.018 and PMC identifier 3776929.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The ATP-dependent chromatin-remodeling complex SWR1 exchanges a variant histone H2A.Z/H2B dimer for a canonical H2A/H2B dimer at nucleosomes flanking histone-depleted regions, such as promoters. This localization of H2A.Z is conserved throughout eukaryotes. SWR1 is a 1 megadalton complex containing 14 different polypeptides, including the AAA+ ATPases Rvb1 and Rvb2. Using electron microscopy, we obtained the three-dimensional structure of SWR1 and mapped its major functional components. Our data show that SWR1 contains a single heterohexameric Rvb1/Rvb2 ring that, together with the catalytic subunit Swr1, brackets two independently assembled multisubunit modules. We also show that SWR1 undergoes a large conformational change upon engaging a limited region of the nucleosome core particle. Our work suggests an important structural role for the Rvbs and a distinct substrate-handling mode by SWR1, thereby providing a structural framework for understanding the complex dimer-exchange reaction.
Medical subject headings
- Adenosine Triphosphatases
- Chromatin Assembly and Disassembly
- DNA Helicases
- Multiprotein Complexes
- Saccharomyces cerevisiae Proteins
- Transcription Factors