Year: 2017
Type: article
Abstract: The Saccharomyces cerevisiae (Sc) R2TP complex affords an Hsp90--mediated scaffolding activity to structurally diverse small ribonucleoprotein particles (snoRNPs).The current lack of structural information on the R2TP complex, however, prevents a mechanistic understanding of this biological process.We have obtained a structural model of the ScR2TP complex made up of two AAA+ ATPases, Rvb1/2p, and two Hsp90 co--chaperone proteins, Tah1p and Pih1p, by a combination of analytical ultracentrifugation, chemical cross--linking, hydrogen-deuterium exchange, and electron cryomicroscopy methods.We find that the Pih1p--Tah1p heterodimer caps the Rvb1/2p heterohexameric ring through its association with the flexible insertion domain of Rvb1/2p and the Pih1p--Tah1p cap is dissociable upon nucleotide binding to Rvb1/2p.Therefore, association of snoRNP intermediates with Pih1p--Tah1p, which is demonstrated for Nop58p here, provides a structural basis for nucleotide--driven binding and release.
Authors: Shaoxiong Tian, Ge Yu, Huan He, Peilu Liu, Alan G. Marshall, Borries Demeler, Scott M. Stagg, Hong Li
Language: English
Topic: Heat shock proteins research
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2778007895