8T2S

Structure of a group II intron ribonucleoprotein in the pre-branching (pre-1F) state

Summary for 8T2S

• Entry DOI: 10.2210/pdb8t2s/pdb
• EMDB information: 40986
• Descriptor: Group II intron reverse transcriptase/maturase, RNA (551-MER), CALCIUM ION, ... (4 entities in total)
• Functional Keywords: rnp, rna, transferase-rna complex, transferase/rna
• Biological source: [Eubacterium] rectale; More
• Total number of polymer chains: 2
• Total formula weight: 260755.25

Authors

Xu, L.,Liu, T.,Chung, K.,Pyle, A.M. (deposition date: 2023-06-06, release date: 2023-11-22, Last modification date: 2024-01-03)

Primary citation

Xu, L.,Liu, T.,Chung, K.,Pyle, A.M.
Structural insights into intron catalysis and dynamics during splicing.
Nature, 624:682-688, 2023

PubMed Abstract: The group II intron ribonucleoprotein is an archetypal splicing system with numerous mechanistic parallels to the spliceosome, including excision of lariat introns. Despite the importance of branching in RNA metabolism, structural understanding of this process has remained elusive. Here we present a comprehensive analysis of three single-particle cryogenic electron microscopy structures captured along the splicing pathway. They reveal the network of molecular interactions that specifies the branchpoint adenosine and positions key functional groups to catalyse lariat formation and coordinate exon ligation. The structures also reveal conformational rearrangements of the branch helix and the mechanism of splice site exchange that facilitate the transition from branching to ligation. These findings shed light on the evolution of splicing and highlight the conservation of structural components, catalytic mechanism and dynamical strategies retained through time in premessenger RNA splicing machines.

PubMed: 37993708
DOI: 10.1038/s41586-023-06746-6

Experimental method

ELECTRON MICROSCOPY (3 Å)