Fig. 3: Structure and function of PRP2 in the human Bact complex.
From: Molecular basis for the activation of human spliceosome
a PRP2 in the Bact-I complex. PRP2 is attached to the peripheral region of the spliceosome and loosely contacts the N-terminal region of SF3B1. N the N-terminus of SF3B1, C the C-terminus of SF3B1. b PRP2 in the Bact-II complex. In the Bact-I to Bact-II transition, PRP2 undergoes a pronounced translocation, moving to the cavity vacated by the RES complex. The PPT sequences of pre-mRNA are loaded into PRP2. c A close-up view on PRP2 in Bact-II. The loop between the N-terminal HEAT repeats of SF3B1 interacts with the RecA2 domain of PRP2, and the BS is anchored on the C-terminal HEAT repeats of SF3B1. The PPT sequences of pre-mRNA are bound to PRP2. d The N-terminal helices of PRP2 directly associate with the C-terminal helices of SKIP, and the linker helix and RRM domain of PPIL4. e A close-up view on the interface between the PPT of pre-mRNA and PRP2. Residues Arg503, Leu709, and Arg998 directly contact the PPT sequences. f Depletion of endogenous PRP2 from the nuclear extract. Compared to the untreated sample, the amount of PRP2 in the nuclear extract is sharply reduced as confirmed by the western blot. g Deletion of the N-terminal extension or mutation of key residues in PRP2 impairs splicing. Shown here are the reverse transcription-PCR results of in vitro splicing reaction. These results have been repeated for three times to confirm the analysis. Source data are provided as a Source Data file.
