Conserved-residue mutations in Wzy affect O-antigen polymerization and Wzz-mediated chain-length regulation in Pseudomonas aeruginosa PAO1
Bibliographic record
Abstract
O antigen (O-Ag) in many bacteria is synthesized via the Wzx/Wzy-dependent pathway in which Wzy polymerizes lipid-linked O-Ag subunits to modal lengths regulated by Wzz. Characterization of 83 site-directed mutants of Wzy from Pseudomonas aeruginosa PAO1 (WzyPa) in topologically-mapped periplasmic (PL) and cytoplasmic loops (CL) verified the functional importance of PL3 and PL5, with the former shown to require overall cationic properties. Essential Arg residues in the RX10G motifs of PL3 and PL5 were found to be conserved in putative homologues of WzyPa, as was the overall sequence homology between these two periplasmic loops in each protein. Amino acid substitutions in CL6 were found to alter Wzz-mediated O-antigen modality, with evidence suggesting that these changes may perturb the C-terminal WzyPa tertiary structure. Together, these data suggest that the catch-and-release mechanism of O-Ag polymerization is widespread among bacteria and that regulation of polymer length is affected by interaction of Wzz with Wzy.
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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) | 0.001 | 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".