AgfC and AgfE facilitate extracellular thin aggregative fimbriae synthesis in Salmonella Enteritidis
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
Salmonella thin aggregative fimbriae (Tafi; curli) are important in pathogenesis and biofilm formation; however, less is known of their structure and morphogenesis. In the Salmonella agfBAC Tafi operon, the transcription and role of agfC have been elusive. In this study, agfBAC transcripts were detected using a sensitive reverse transcriptase technique. Native AgfC was not detected using polyclonal antibodies generated against purified hexahistidine-tagged AgfC; however, in trans expression revealed that AgfC was localized to the periplasm as a mature form. An isogenic DeltaagfC mutant displayed an abundance of 20 nm fibres, in addition to native Tafi (5-7 nm), and had an increase in cell surface hydrophobicity. Purified 20 nm fibres were depolymerized under exceptionally stringent conditions to release what proved to be AgfA subunits. This revealed that the 20 nm fibres represented a different form of Tafi. The role of AgfC in Tafi assembly was investigated further using an antibody-capture assay of isogenic Deltaagf mutants. A soluble antibody-accessible form of AgfA was captured in wild-type (wt), DeltaagfB and DeltaagfF strains, in support of the extracellular nucleation-precipitation pathway of Tafi assembly, but not in DeltaagfC or DeltaagfE mutants. This indicates that AgfC and AgfE are important for AgfA extracellular assembly, facilitating the synthesis of Tafi.
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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 | 0.000 |
| 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 it