Seraphim Thiago V, Nano Nardin, Cheung Yiu Wing Sunny, Aluksanasuwan Siripat, Colleti Carolina, Mao Yu-Qian, Bhandari Vaibhav, Young Gavin, Höll Larissa, Phanse Sadhna, Gordiyenko Yuliya, Southworth Daniel R, Robinson Carol V, Thongboonkerd Visith, Gava Lisandra M, Borges Júlio C, Babu Mohan, Barbosa Leandro R S, Ramos Carlos H I, Kukura Philipp, Houry Walid A
Department of Biochemistry, University of Toronto, 661 University Avenue, MaRS Centre, West Tower, Room 1612, Toronto, ON M5G 1M1, Canada; Department of Chemistry and Biochemistry, University of Regina, Regina, SK S4S 0A2, Canada.
Department of Biochemistry, University of Toronto, 661 University Avenue, MaRS Centre, West Tower, Room 1612, Toronto, ON M5G 1M1, Canada.
Structure. 2022 Jan 6;30(1):156-171.e12. doi: 10.1016/j.str.2021.08.002. Epub 2021 Sep 6.
R2TP is a highly conserved chaperone complex formed by two AAA+ ATPases, RUVBL1 and RUVBL2, that associate with PIH1D1 and RPAP3 proteins. R2TP acts in promoting macromolecular complex formation. Here, we establish the principles of R2TP assembly. Three distinct RUVBL1/2-based complexes are identified: R2TP, RUVBL1/2-RPAP3 (R2T), and RUVBL1/2-PIH1D1 (R2P). Interestingly, we find that PIH1D1 does not bind to RUVBL1/RUVBL2 in R2TP and does not function as a nucleotide exchange factor; instead, RPAP3 is found to be the central subunit coordinating R2TP architecture and linking PIH1D1 and RUVBL1/2. We also report that RPAP3 contains an intrinsically disordered N-terminal domain mediating interactions with substrates whose sequences are primarily enriched for Armadillo repeat domains and other helical-type domains. Our work provides a clear and consistent model of R2TP complex structure and gives important insights into how a chaperone machine concerned with assembly of folded proteins into multisubunit complexes might work.
R2TP是一种由两个AAA+ ATP酶RUVBL1和RUVBL2形成的高度保守的伴侣蛋白复合体，它们与PIH1D1和RPAP3蛋白相关联。R2TP在促进大分子复合体形成方面发挥作用。在此，我们确立了R2TP组装的原理。鉴定出三种不同的基于RUVBL1/2的复合体：R2TP、RUVBL1/2-RPAP3（R2T）和RUVBL1/2-PIH1D1（R2P）。有趣的是，我们发现PIH1D1在R2TP中不与RUVBL1/RUVBL2结合，也不充当核苷酸交换因子；相反，发现RPAP3是协调R2TP结构并连接PIH1D1和RUVBL1/2的核心亚基。我们还报告称，RPAP3包含一个内在无序的N端结构域，介导与底物的相互作用，这些底物的序列主要富含犰狳重复结构域和其他螺旋型结构域。我们的工作提供了一个清晰且一致的R2TP复合体结构模型，并对一个与将折叠蛋白组装成多亚基复合体相关的伴侣蛋白机器可能如何工作提供了重要见解。
