α‐Galacturonidase(s): A new class of Family 4 glycoside hydrolases with strict specificity and a unique CHEV active site motif
Bibliographic record
Abstract
The catalytic activity of the Family 4 glycosidase LplD protein, whose active site motif is CHEV, is unknown despite its crystal structure having been determined in 2008. Here we identify that activity as being an α-galacturonidase whose natural substrate is probably α-1,4-di-galacturonate (GalUA2). Phylogenetic analysis shows that LplD belongs to a monophyletic clade of CHEV Family 4 enzymes, of which four other members are also shown to be galacturonidases. Family GH 4 enzymes catalyze the cleavage of the glycosidic bond, via a non-canonical redox-assisted mechanism that contrasts with Koshland's double-displacement mechanism.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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 teacher head, 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".