Rxivist logo

Structure of the TELO2-TTI1-TTI2 complex and its function in TOR recruitment to the R2TP chaperone

By Mohinder Pal, Hugo Muñoz-Hernandez, Dennis Bjorklund, Lihong Zhou, Gianluca Degliesposti, J. Mark Skehel, Emma L. Hesketh, Rebecca F. Thompson, Laurence H Pearl, Oscar Llorca, Chrisostomos Prodromou

Posted 09 Nov 2020
bioRxiv DOI: 10.1101/2020.11.09.374355

The R2TP (RUVBL1-RUVBL2-RPAP3-PIH1D1) complex, in collaboration with HSP90, functions as a chaperone for the assembly and stability of protein complexes, including RNA polymerases, snRNPs and PI3 kinase-like kinases (PIKK) such as TOR and SMG1. PIKK stabilisation depends on an additional complex of TELO2, TTI1 and TTI2 (TTT), whose structure and function are poorly understood. We have now determined the cryo-EM structure of the human R2TP-TTT complex that together with biochemical experiments reveals the mechanism of TOR recruitment to the R2TP-TTT chaperone. The HEAT-repeat TTT complex binds the kinase domain of TOR, without blocking its activity, and delivers TOR to the R2TP chaperone. In addition, TTT regulates the R2TP chaperone by inhibiting RUVBL1-RUVBL2 ATPase activity and by modulating the conformation and interactions of the PIH1D1 and RPAP3 components of R2TP. Together, our results show how TTT couples the recruitment of TOR to R2TP with the regulation of this chaperone system. ### Competing Interest Statement The authors have declared no competing interest.

Download data

  • Downloaded 377 times
  • Download rankings, all-time:
    • Site-wide: 72,651
    • In biochemistry: 2,010
  • Year to date:
    • Site-wide: 30,396
  • Since beginning of last month:
    • Site-wide: 24,590

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide