Subunit Rtt102 controls the conformation of the Arp7/9 heterodimer and its interactions with nucleotide and the catalytic subunit of SWI/SNF remodelers

Bengi Turegun, David J. Kast, Roberto Dominguez

Research output: Contribution to journalArticlepeer-review

5 Scopus citations

Abstract

Chromatin-remodeling complexes are assembled around a catalytic subunit that contains a central ATPase domain and flanking sequences that recruit auxiliary subunits. The catalytic subunits of SWI/SNF remodelers recruit Arp7/9 through a helicase/SANT-associated (HSA) domain N-terminal to the ATPase domain. Arp7/9-containing remodelers also carry the auxiliary subunit Rtt102, but the role of this subunit is poorly understood. Here, we show that Rtt102 binds with nanomolar affinity to the Arp7/9 heterodimer and modulates its conformation and interactions with the ATPase subunit and nucleotide. When bound to Rtt102, Arp7/9 interacts with a shorter segment of the HSA domain. Structural analysis by small-angle x-ray scattering further shows that when bound to Rtt102, the complex of Arp7/9 with the catalytic subunit assumes a more stable compact conformation. We also found that Arp7, Arp9, and Arp7/9 interact very weakly with ATP, but Rtt102 promotes high-affinity ATP binding to a single site in the heterodimer. Collectively, the results establish a function for subunit Rtt102 as a stabilizing factor for the Arp7/9 heterodimer, enhancing its interaction with nucleotide and controlling the conformation of SWI/SNF remodelers in an Arp7/9-dependent manner.

Original languageEnglish
Pages (from-to)35758-35768
Number of pages11
JournalJournal of Biological Chemistry
Volume288
Issue number50
DOIs
StatePublished - Dec 13 2013
Externally publishedYes

Fingerprint Dive into the research topics of 'Subunit Rtt102 controls the conformation of the Arp7/9 heterodimer and its interactions with nucleotide and the catalytic subunit of SWI/SNF remodelers'. Together they form a unique fingerprint.

Cite this