A common molecular signature unifies the chitosanases belonging to families 46 and 80 of glycoside hydrolases
Bibliographic record
Abstract
The 3D structure-oriented alignment of the primary sequences of fourteen chitosanases, mainly of bacterial origin and belonging to families 46 and 80 of glycoside hydrolases, resulted in the identification of the following pattern common to all these enzymes: E-[DNQ]-x(8,17)-Y-x(7)-D-x-[RD]-[GP]-x-[TS]-x(3)-[AIVFLY]-G-x(5,11)-D. This pattern is proposed as the molecular signature of the chitosanases from families 46 and 80. It includes several amino acids essential for enzyme activity and (or) stability as shown by site-directed mutagenesis studies on the chitosanase from Streptomyces sp. N174. In particular, it includes two carboxylic residues directly involved in catalysis. We suggest that there is a continuum of sequence similarity between all the analyzed chitosanases, and that all these enzymes should probably be classified in one family.Key words: chitosanase, glycosyl hydrolase, protein motif.
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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) | 0.000 | 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; 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".