Summary information and primary citation
- PDB-id
- 7abh; SNAP-derived features in text and JSON formats;
DNAproDB
- Class
- splicing
- Method
- cryo-EM (4.5 Å)
- Summary
- Human pre-bact-2 spliceosome (sf3b-u2 snrnp portion)
- Reference
- Townsend C, Leelaram MN, Agafonov DE, Dybkov O, Will CL, Bertram K, Urlaub H, Kastner B, Stark H, Luhrmann R (2020): "Mechanism of protein-guided folding of the active site U2/U6 RNA during spliceosome activation." Science, 370. doi: 10.1126/science.abc3753.
- 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 pre-Bact complexes at core resolutions of 3.9-4.2 Å. 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 Bact complexes reveal the molecular mechanism whereby a conformational change in the scaffold protein PRP8 facilitates final 3D folding of the U2/U6 catalytic RNA.
