Summary information and primary citation
- PDB-id
-
5gan;
DSSR-derived features in text and
JSON formats
- Class
- transcription
- Method
- cryo-EM (3.7 Å)
- Summary
- The overall structure of the yeast spliceosomal
u4-u6.u5 tri-snrnp at 3.7 angstrom
- Reference
-
Nguyen TH, Galej WP, Bai XC, Oubridge C, Newman AJ,
Scheres SH, Nagai K (2016): "Cryo-EM
structure of the yeast U4/U6.U5 tri-snRNP at 3.7 angstrom
resolution." Nature, 530,
298-302. doi: 10.1038/nature16940.
- Abstract
- U4/U6.U5 tri-snRNP represents a substantial part of the
spliceosome before activation. A cryo-electron microscopy
structure of Saccharomyces cerevisiae U4/U6.U5 tri-snRNP at
3.7 Å resolution led to an essentially complete atomic
model comprising 30 proteins plus U4/U6 and U5 small
nuclear RNAs (snRNAs). The structure reveals striking
interweaving interactions of the protein and RNA
components, including extended polypeptides penetrating
into subunit interfaces. The invariant ACAGAGA sequence of
U6 snRNA, which base-pairs with the 5'-splice site during
catalytic activation, forms a hairpin stabilized by Dib1
and Prp8 while the adjacent nucleotides interact with the
exon binding loop 1 of U5 snRNA. Snu114 harbours GTP, but
its putative catalytic histidine is held away from the
γ-phosphate by hydrogen bonding to a tyrosine in the
amino-terminal domain of Prp8. Mutation of this histidine
to alanine has no detectable effect on yeast growth. The
structure provides important new insights into the
spliceosome activation process leading to the formation of
the catalytic centre.
