Membrane Sequestration of PII Proteins and Nitrogenase Regulation in the Photosynthetic Bacterium <i>Rhodobacter capsulatus</i>
Bibliographic record
Abstract
Both Rhodobacter capsulatus PII homologs GlnB and GlnK were found to be necessary for the proper regulation of nitrogenase activity and modification in response to an ammonium shock. As previously reported for several other bacteria, ammonium addition triggered the AmtB-dependent association of GlnK with the R. capsulatus membrane. Native polyacrylamide gel electrophoresis analysis indicates that the modification/demodification of one PII homolog is aberrant in the absence of the other. In a glnK mutant, more GlnB was found to be membrane associated under these conditions. In a glnB mutant, GlnK fails to be significantly sequestered by AmtB, even though it appears to be fully deuridylylated. Additionally, the ammonium-induced enhanced sequestration by AmtB of the unmodifiable GlnK variant GlnK-Y51F follows the wild-type GlnK pattern with a high level in the cytoplasm without the addition of ammonium and an increased level in the membrane fraction after ammonium treatment. These results suggest that factors other than PII modification are driving its association with AmtB in the membrane in R. capsulatus.
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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) | 0.000 | 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 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".