The structure of the <i>Gemella haemolysans</i> M26 IgA1 protease trypsin-like domain
Bibliographic record
Abstract
Immunoglobulin A (IgA) proteases are a group of bacterial-derived enzymes that selectivity hydrolyze human IgA in the hinge region that is unique to this immunoglobulin. Several IgA protease (IgAP) families have evolved this ability using both metalloprotease and serine protease chemical mechanisms. One family of metal-dependent IgAPs is the M26 family. This family can be grouped into two subfamilies based upon the presence or absence of a trypsin-like domain found N-terminal to the IgAP domain. The role of this domain in IgAP structure and function is poorly understood. Here, we present the first structural characterization of an M26 IgAP trypsin-like domain from Gemella haemolysans (GhTrp). These structural data demonstrate that the GhTrp domain possesses a trypsin-like fold but contains significant deviations in the surface-loop structure that is known to be coupled to protease selectivity. The lack of observable catalytic function coupled with the structural data suggest that this domain may exist in a pro-enzyme-like state that can potentially be activated when the domain is N-terminally proteolytically excised from the larger M26 IgAP structure.
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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 | 0.001 |
| Science and technology studies | 0.003 | 0.003 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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 itClassification
machine, unvalidatedMachine predicted; both teacher heads agree on what is shown here.
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".