The complete set of H/ACA snoRNAs that guide rRNA pseudouridylations in <i>Saccharomyces cerevisiae</i>
Bibliographic record
Abstract
Conversion of uridines into pseudouridines (Psis) is the most frequent base modification in ribosomal RNAs (rRNAs). In eukaryotes, the pseudouridylation sites are specified by base-pairing with specific target sequences within H/ACA small nucleolar RNAs (snoRNAs). The yeast rRNAs harbor 44 Psis, but, when this work began, 15 Psis had completely unknown guide snoRNAs. This suggested that many snoRNAs remained to be discovered. To address this problem and further complete the snoRNA assignment to Psi sites, we identified the complete set of RNAs associated with the H/ACA snoRNP specific proteins Gar1p and Nhp2p by coupling TAP-tag purifications with genomic DNA microarrays experiments. Surprisingly, while we identified all the previously known H/ACA snoRNAs, we selected only three new snoRNAs. This suggested that most of the missing Psi guides were present in previously known snoRNAs but had been overlooked. We confirmed this hypothesis by systematically investigating the role of previously known, as well as of the newly identified snoRNAs, in specifying rRNA Psi sites and found all but one missing guide RNAs. During the completion of this work, another study, based on bioinformatic predictions, also reported the identification of most missing guide RNAs. Altogether, all Psi guides are now identified and we can tell that, in budding yeast, the 44 Psis are guided by 28 snoRNAs. Finally, aside from snR30, an atypical small RNA of heterogeneous length and at least one mRNA, all Gar1p and Nhp2p associated RNAs characterized by our work turned out to be snoRNAs involved in rRNA Psi specification.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".