Summary information and primary citation
- PDB-id
-
6icz;
DSSR-derived features in text and
JSON formats
- Class
- splicing
- Method
- cryo-EM (3.0 Å)
- Summary
- cryo-EM structure of a human post-catalytic spliceosome
(p complex) at 3.0 angstrom
- Reference
-
Zhang X, Zhan X, Yan C, Zhang W, Liu D, Lei J, Shi Y
(2019): "Structures
of the human spliceosomes before and after release of the
ligated exon." Cell Res.,
29, 274-285. doi: 10.1038/s41422-019-0143-x.
- Abstract
- Pre-mRNA splicing is executed by the spliceosome, which
has eight major functional states each with distinct
composition. Five of these eight human spliceosomal
complexes, all preceding exon ligation, have been
structurally characterized. In this study, we report the
cryo-electron microscopy structures of the human
post-catalytic spliceosome (P complex) and intron lariat
spliceosome (ILS) at average resolutions of 3.0 and 2.9 Å,
respectively. In the P complex, the ligated exon remains
anchored to loop I of U5 small nuclear RNA, and the
3'-splice site is recognized by the junction between the
5'-splice site and the branch point sequence. The
ATPase/helicase Prp22, along with the ligated exon and
eight other proteins, are dissociated in the P-to-ILS
transition. Intriguingly, the ILS complex exists in two
distinct conformations, one with the ATPase/helicase Prp43
and one without. Comparison of these three late-stage human
spliceosomes reveals mechanistic insights into exon release
and spliceosome disassembly.
