8H6K

Cryo-EM structure of human exon-defined spliceosome in the mature B state.

This is a non-PDB format compatible entry.

Summary for 8H6K

• Entry DOI: 10.2210/pdb8h6k/pdb
• Related: 8H6E 8H6J
• EMDB information: 34500 34505 34507
• Descriptor: pre-mRNA, Small nuclear ribonucleoprotein F, Small nuclear ribonucleoprotein E, ... (53 entities in total)
• Functional Keywords: exon-defined spliceosome, post pre-b state, splicing
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 63
• Total formula weight: 2629833.02

Authors

Zhang, W.,Zhan, X.,Zhang, X.,Bai, R.,Lei, J.,Yan, C.,Shi, Y. (deposition date: 2022-10-18, release date: 2024-05-01, Last modification date: 2024-10-30)

Primary citation

Zhang, W.,Zhang, X.,Zhan, X.,Bai, R.,Lei, J.,Yan, C.,Shi, Y.
Structural insights into human exon-defined spliceosome prior to activation.
Cell Res., 34:428-439, 2024

PubMed Abstract: Spliceosome is often assembled across an exon and undergoes rearrangement to span a neighboring intron. Most states of the intron-defined spliceosome have been structurally characterized. However, the structure of a fully assembled exon-defined spliceosome remains at large. During spliceosome assembly, the pre-catalytic state (B complex) is converted from its precursor (pre-B complex). Here we report atomic structures of the exon-defined human spliceosome in four sequential states: mature pre-B, late pre-B, early B, and mature B. In the previously unknown late pre-B state, U1 snRNP is already released but the remaining proteins are still in the pre-B state; unexpectedly, the RNAs are in the B state, with U6 snRNA forming a duplex with 5'-splice site and U5 snRNA recognizing the 3'-end of the exon. In the early and mature B complexes, the B-specific factors are stepwise recruited and specifically recognize the exon 3'-region. Our study reveals key insights into the assembly of the exon-defined spliceosomes and identifies mechanistic steps of the pre-B-to-B transition.

PubMed: 38658629
DOI: 10.1038/s41422-024-00949-w

Experimental method

ELECTRON MICROSCOPY (2.7 Å)