7ABI

Human pre-Bact-2 spliceosome

Summary for 7ABI

• Entry DOI: 10.2210/pdb7abi/pdb
• Related: 7AAV 7ABF 7ABG 7ABH
• EMDB information: 11693 11694 11695 11696 11697
• Descriptor: U5 small nuclear ribonucleoprotein 40 kDa protein, U2 small nuclear ribonucleoprotein B'', Splicing factor 3B subunit 6, ... (52 entities in total)
• Functional Keywords: complex, spliceosome, catalytic activation, splicing
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 56
• Total formula weight: 3129426.49

Authors

Townsend, C.,Kastner, B.,Leelaram, M.N.,Bertram, K.,Stark, H.,Luehrmann, R. (deposition date: 2020-09-07, release date: 2021-02-10, Last modification date: 2025-04-09)

Primary citation

Townsend, C.,Leelaram, M.N.,Agafonov, D.E.,Dybkov, O.,Will, C.L.,Bertram, K.,Urlaub, H.,Kastner, B.,Stark, H.,Luhrmann, R.
Mechanism of protein-guided folding of the active site U2/U6 RNA during spliceosome activation.
Science, 370:-, 2020

PubMed Abstract: Spliceosome activation involves extensive protein and RNA rearrangements that lead to formation of a catalytically active U2/U6 RNA structure. At present, little is known about the assembly pathway of the latter and the mechanism whereby proteins aid its proper folding. Here, we report the cryo-electron microscopy structures of two human, activated spliceosome precursors (that is, pre-B complexes) at core resolutions of 3.9 and 4.2 angstroms. These structures elucidate the order of the numerous protein exchanges that occur during activation, the mutually exclusive interactions that ensure the correct order of ribonucleoprotein rearrangements needed to form the U2/U6 catalytic RNA, and the stepwise folding pathway of the latter. Structural comparisons with mature B complexes reveal the molecular mechanism whereby a conformational change in the scaffold protein PRP8 facilitates final three-dimensional folding of the U2/U6 catalytic RNA.

PubMed: 33243851
DOI: 10.1126/science.abc3753

Experimental method

ELECTRON MICROSCOPY (8 Å)