Pih1p-Tah1p puts a lid on hexameric AAA+ ATPases Rvb1/2p
Marshall, Alan G.
Stagg, Scott M.
The Saccharomyces cerevisiae (Sc) R2TP complex affords an Hsp90-mediated and nucleotide-driven chaperone activity to proteins of small ribonucleoprotein particles (snoRNPs). The current lack of structural information on the ScR2TP complex, however, prevents a mechanistic understanding of this biological process. We characterized the structure of the ScR2TP complex made up of two AAA+ ATPases, Rvb1/2p, and two Hsp90 binding proteins, Tah1p and Pih1p, and its interaction with the snoRNP protein Nop58p by a combination of analytical ultracentrifugation, isothermal titration calorimetry, chemical crosslinking, hydrogen-deuterium exchange, and cryoelectron microscopy methods. We find that Pih1p-Tah1p interacts with Rvb1/2p cooperatively through the nucleotide-sensitive domain of Rvb1/2p. Nop58p further binds Pih1p-Tahp1 on top of the dome-shaped R2TP. Consequently, nucleotide binding releases Pih1p-Tah1p from Rvb1/2p, which offers a mechanism for nucleotide-driven binding and release of snoRNP intermediates.
Accepted author manuscript
Rvb1 , Rvb2 , AAA+ proteins , Cryoelectron microscopy , Fourier transform mass spectrometry , Ion cyclotron resonance , FT-ICR , FTMS , Hydrogen/deuterium exchange , Analytical ultracentrifugation
Tian, S., Yu, G., He, H., Zhao, Y., Liu, P., Marshall, A. G., Demeler, B., Stagg, S. M., & Li, H. (2017). Pih1p-Tah1p puts a lid on hexameric AAA+ ATPases Rvb1/2p. Structure, 25(10), 1519-1529. http://dx.doi.org/10.1016/j.str.2017.08.002