Stress-induced Pseudouridylation Alters the Structural Equilibrium of Yeast U2 snRNA Stem II.

ABSTRACT: In yeast, the U2 small nuclear ribonucleic acid (snRNA) component of the spliceosome is targeted for additional post-transcriptional modifications in response to cellular stress. Uridines 56 and 93 are both modified to pseudouridines (Ψ) during nutrient deprivation, while U56 is also pseudouridylated during heat shock. Both positions are located within stem II, which must toggle between two mutually exclusive structures during splicing. Stem IIa forms during spliceosome assembly, and stem IIc forms during the catalytic steps. We have studied how uridine 56 and 93 pseudouridylation impacts conformational switching of stem II. Using single-molecule Förster resonance energy transfer, we show that Ψ56 dampens conformational dynamics of stem II and stabilizes stem IIc. In contrast, Ψ93 increase

SUBMITTER: van der Feltz C 

PROVIDER: S-EPMC5805610 | biostudies-literature | 2018 Feb

REPOSITORIES: biostudies-literature