Extended Data Figure 10: Structural changes in the spliceosome that are probably mediated by the action of PRP16.
From: Cryo-EM structure of a human spliceosome activated for step 2 of splicing
a, b, Comparison of the position/orientation of the PRP8 RH domain, U2 Sm core plus U2-A′ (S. cerevisiae Lea1) and U2-B′′ (S. cerevisiae Msl1), SYF1 and SYF3 HAT repeats, PRP17 WD40 domain and the catalytic RNA core, aligned relative to the PRP8 En/RT domain, in the S. cerevisiae C complex and the human C* complex. Black circle, catalytic centre. Asterisk, position of the β-hairpin loop of the RH domain. Structural changes probably facilitated by PRP16 include: (1) repositioning of the extended branched intron structure away from the catalytic centre together with a similar movement of the PRP17 WD40 domain; (2) a large scale movement of the entire 3′ domain of U2 snRNP and rearrangement of SYF1 and SYF3; (3) translocation of the PRP8 RH domain by approximately 35 Å (bottom) to 60 Å (tip of β-hairpin loop) such that it interacts with the branched intron structure in the C* complex; (4) rearrangement of the PRP8 α-finger; and (5) destabilization of Yju2/CCDC130 and Cwc25/CWC25.