Actin-related proteins regulate the RSC chromatin remodeler by weakening intramolecular interactions of the Sth1 ATPase.Turegun, B., Baker, R.W., Leschziner, A.E., Dominguez, R.
(2018) Commun Biol 1: --
- PubMed: 29809203
- DOI: 10.1038/s42003-017-0002-6
- PubMed Abstract:
The catalytic subunits of SWI/SNF-family and INO80-family chromatin remodelers bind actin and actin-related proteins (Arps) through an N-terminal helicase/SANT-associated (HSA) domain. Between the HSA and ATPase domains lies a conserved post-HSA (pHS ...
The catalytic subunits of SWI/SNF-family and INO80-family chromatin remodelers bind actin and actin-related proteins (Arps) through an N-terminal helicase/SANT-associated (HSA) domain. Between the HSA and ATPase domains lies a conserved post-HSA (pHSA) domain. The HSA domain of Sth1, the catalytic subunit of the yeast SWI/SNF-family remodeler RSC, recruits the Rtt102-Arp7/9 heterotrimer. Rtt102-Arp7/9 regulates RSC function, but the mechanism is unclear. We show that the pHSA domain interacts directly with another conserved region of the catalytic subunit, protrusion-1. Rtt102-Arp7/9 binding to the HSA domain weakens this interaction and promotes the formation of stable, monodisperse complexes with DNA and nucleosomes. A crystal structure of Rtt102-Arp7/9 shows that ATP binds to Arp7 but not Arp9. However, Arp7 does not hydrolyze ATP. Together, the results suggest that Rtt102 and ATP stabilize a conformation of Arp7/9 that potentiates binding to the HSA domain, which releases intramolecular interactions within Sth1 and controls DNA and nucleosome binding.
Department of Physiology, Perelman School of Medicine, University of Pennsylvania, 728 Clinical Research Building, 415 Curie Boulevard, Philadelphia, PA 19104-6085, USA.,Department of Cellular and Molecular Medicine, School of Medicine, and Section of Molecular Biology, Division of Biological Sciences, UC San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.