YghG (GspS <sub>β</sub> ) Is a Novel Pilot Protein Required for Localization of the GspS <sub>β</sub> Type II Secretion System Secretin of Enterotoxigenic Escherichia coli
Bibliographic record
Abstract
The enterotoxigenic Escherichia coli (ETEC) pathotype, characterized by the prototypical strain H10407, is a leading cause of morbidity and mortality in the developing world. A major virulence factor of ETEC is the type II secretion system (T2SS) responsible for secretion of the diarrheagenic heat-labile enterotoxin (LT). In this study, we have characterized the two type II secretion systems, designated alpha (T2SS(α)) and beta (T2SS(β)), encoded in the H10407 genome and describe the prevalence of both systems in other E. coli pathotypes. Under laboratory conditions, the T2SS(β) is assembled and functional in the secretion of LT into culture supernatant, whereas the T2SS(α) is not. Insertional inactivation of the three genes located upstream of gspC(β) (yghJ, pppA, and yghG) in the atypical T2SS(β) operon revealed that YghJ is not required for assembly of the GspD(β) secretin or secretion of LT, that PppA is likely the prepilin peptidase required for the function of T2SS(β), and that YghG is required for assembly of the GspD(β) secretin and thus function of the T2SS(β). Mutational and physiological analysis further demonstrated that YghG (redesignated GspS(β)) is a novel outer membrane pilotin protein that is integral for assembly of the T2SS(β) by localizing GspD(β) to the outer membrane, whereupon GspD(β) forms the macromolecular secretin multimer through which T2SS(β) substrates are translocated.
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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) | 0.000 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".