The spliceosome undergoes dramatic changes in a splicing cycle. Structures of B, Bact, C, C*, and intron lariat spliceosome complexes revealed mechanisms of 5'-splice site (ss) recognition, branching, and intron release, but lacked information on 3'-ss recognition, exon ligation, and exon release. Here we report a cryo-electron microscopy structure of the postcatalytic P complex at 3.3-angstrom resolution, revealing that the 3' ss is mainly recognized through non-Watson-Crick base pairing with the 5' ss and branch point. Furthermore, one or more unidentified proteins become stably associated with the P complex, securing the 3' exon and potentially regulating activity of the helicase Prp22. Prp22 binds nucleotides 15 to 21 in the 3' exon, enabling it to pull the intron-exon or ligated exons in a 3' to 5' direction to achieve 3'-ss proofreading or exon release, respectively.
Evidence for an essential non-Watson-Crick interaction between the first and last nucleotides of a nuclear pre-mRNA intron
Epitope tagging of yeast genes using a PCR-based strategy: more tags and improved practical routines
Optimal determination of particle orientation, absolute hand, and contrast loss in single-particle electron cryomicroscopy
Interaction between a G-patch protein and a spliceosomal DEXD/H-box ATPase that is critical for splicing
Deciphering 3'ss selection in the yeast genome reveals an RNA thermosensor that mediates alternative splicing
Molecular dissection of step 2 catalysis of yeast pre-mRNA splicing investigated in a purified system
High-resolution noise substitution to measure overfitting and validate resolution in 3D structure determination by single particle electron cryomicroscopy
The G-patch protein Spp2 couples the spliceosome-stimulated ATPase activity of the DEAH-box protein Prp2 to catalytic activation of the spliceosome
Structure of the DEAH/RHA ATPase Prp43p bound to RNA implicates a pair of hairpins and motif Va in translocation along RNA
A Genetic Screen Identifies PRP18a, a Putative Second Step Splicing Factor Important for Alternative Splicing and a Normal Phenotype in Arabidopsis thaliana
A two-step probing method to compare lysine accessibility across macromolecular complex conformations
Structural and functional characterisation of human RNA helicase DHX8 provides insights into the mechanism of RNA-stimulated ADP release
Termination of pre-mRNA splicing requires that the ATPase and RNA unwindase Prp43p acts on the catalytic snRNA U6
Cus2 enforces the first ATP-dependent step of splicing by binding to yeast SF3b1 through a UHM-ULM interaction
Structural dynamics of the N-terminal domain and the Switch loop of Prp8 during spliceosome assembly and activation
A human postcatalytic spliceosome structure reveals essential roles of metazoan factors for exon ligation
Prp8 in a Reduced Spliceosome Lacks a Conserved Toggle that Correlates with Splicing Complexity across Diverse Taxa
The structure of Prp2 bound to RNA and ADP-BeF3- reveals structural features important for RNA unwinding by DEAH-box ATPases.
F2X-Universal and F2X-Entry: Structurally Diverse Compound Libraries for Crystallographic Fragment Screening.
Alternative splicing a regulated gene expression process that allows a single genetic sequence to code for multiple proteins. Here is that latest research.