Summary information and primary citation

PDB-id
5g2x; DSSR-derived features in text and JSON formats
Class
transferase
Method
cryo-EM (3.8 Å)
Summary
Structure a of group ii intron complexed with its reverse transcriptase
Reference
Qu G, Kaushal PS, Wang J, Shigematsu H, Piazza CL, Agrawal RK, Belfort M, Wang H (2016): "Structure of a Group II Intron in Complex with its Reverse Transcriptase." Nat.Struct.Mol.Biol., 23, 549. doi: 10.1038/NSMB.3220.
Abstract
Bacterial group II introns are large catalytic RNAs related to nuclear spliceosomal introns and eukaryotic retrotransposons. They self-splice, yielding mature RNA, and integrate into DNA as retroelements. A fully active group II intron forms a ribonucleoprotein complex comprising the intron ribozyme and an intron-encoded protein that performs multiple activities including reverse transcription, in which intron RNA is copied into the DNA target. Here we report cryo-EM structures of an endogenously spliced Lactococcus lactis group IIA intron in its ribonucleoprotein complex form at 3.8-Å resolution and in its protein-depleted form at 4.5-Å resolution, revealing functional coordination of the intron RNA with the protein. Remarkably, the protein structure reveals a close relationship between the reverse transcriptase catalytic domain and telomerase, whereas the active splicing center resembles the spliceosomal Prp8 protein. These extraordinary similarities hint at intricate ancestral relationships and provide new insights into splicing and retromobility.

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