From: Dynamic protein–RNA interactions in mediating splicing catalysis Figure 3. Analysis of total crosslinked proteins at the BS-3′SS region. Splicing was carried out using actin ACAC (A–E) or wild-type pre-mRNA (F and G) with 4sU labeled in the BS-3′SS region at indicated positions in Spp2-depleted Hsh155-HA extracts (A), Yju2-depleted extracts (B), Prp16-depleted Cwc25-HA extracts (C), in the presence of prp16-D473A protein (D), in Prp22-V5 extracts (E and G), in the presence of prp22-S635A-V5 protein (F), or in Slu7/Prp22-depleted extracts (G). Following UV-irradiation, the spliceosome was precipitated with anti-HA (A and C), anti-Ntc20 (B and G), anti-Prp16 (D) or anti-V5 (E and F) antibody. Total crosslinked proteins were analyzed on 4–20% gradient SDS-PAGE. Two major crosslinked products of unknown identity are marked as ? (A–D, G) and ?? (D), respectively. From: Dynamic protein–RNA interactions in mediating splicing catalysis Nucleic Acids Res. Published online November 05, 2018. doi:10.1093/nar/gky1089 Nucleic Acids Res | © The Author(s) 2018. Published by Oxford University Press on behalf of Nucleic Acids Research.This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com 1