Golgi α-mannosidase II cleaves two sugars sequentially in the same catalytic site
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Golgi alpha-mannosidase II (GMII) is a key glycosyl hydrolase in the N-linked glycosylation pathway. It catalyzes the removal of two different mannosyl linkages of GlcNAcMan(5)GlcNAc(2), which is the committed step in complex N-glycan synthesis. Inhibition of this enzyme has shown promise in certain cancers in both laboratory and clinical settings. Here we present the high-resolution crystal structure of a nucleophile mutant of Drosophila melanogaster GMII (dGMII) bound to its natural oligosaccharide substrate and an oligosaccharide precursor as well as the structure of the unliganded mutant. These structures allow us to identify three sugar-binding subsites within the larger active site cleft. Our results allow for the formulation of the complete catalytic process of dGMII, which involves a specific order of bond cleavage, and a major substrate rearrangement in the active site. This process is likely conserved for all GMII enzymes-but not in the structurally related lysosomal mannosidase-and will form the basis for the design of specific inhibitors against GMII.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 it