Nickel translocation between metallochaperones HypA and UreE in Helicobacter pylori
Bibliographic record
Abstract
Incorporation of nickel ions to the active sites of urease and hydrogenase is prerequisite for the appropriate functions of the metalloenzymes. Such a process requires the participation of several accessory proteins. Interestingly, some of them are shared by the two enzymes in their maturation processes. In this work, we characterized the molecular details of the interaction of metallochaperones UreE and HypA in Helicobacter pylori. We show by chemical cross-linking and static light scattering that the UreE dimer binds to HypA to form a hetero-complex i.e. HypA-(UreE)2. The dissociation constant (Kd) of the protein complex was determined by ITC to be 1 μM in the absence of nickel ions; whereas binding of Ni(2+) but not Zn(2+) to UreE resulted in ca. one fold decrease in the affinity. The putative interfaces on HypA unveiled by NMR chemical shift perturbation were found mainly at the nickel binding domain and in the cleft between α1 and β1/β6. We also identified that the C-domain of UreE, in particular the C-terminal residues of 158-170 are indispensable for the interaction of UreE and HypA. Such an interaction was also observed intracellularly by GFP-fragment reassembly assay. Moreover, we demonstrated using a fluorescent probe that nickel is transferred from HypA to UreE via the specific protein-protein interaction. Deletion of the C-terminus (residues 158-170) of UreE abolished nickel transfer and led to a significant decrease in urease activity. This study provides direct in vitro and in vivo evidence as well as molecular details of nickel translocation mediated by protein-protein interaction.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".