Preliminary structural characterization of a methyltransferase involved in rhodoquinone biosynthesis
Bibliographic record
Abstract
The primary process of energy production for most eukaryotes involves oxidative respiration via the electron transport chain (ETC). In the ETC, electrons are moved by the electron carrier ubiquinone through membrane‐bound protein complexes that pump protons across the mitochondrial membrane, which creates a proton chemical gradient. This gradient is used to produce adenosine triphosphate, which is the primary source of energy in the cell. Oxygen is the final electron acceptor of the ETC for aerobic organisms, but for organisms that live in low‐oxygen environments, other strategies are required for the ETC to function. One strategy used by many species of bacteria and protists is to produce rhodoquinone, which is a derivative of ubiquinone. Rhodoquinone allows the ETC to function in the absence of oxygen by allowing it to use fumarate as the final electron acceptor. RQ is synthesized by the enzyme RquA, which likely uses ubiquinone as a substrate. Our goal is to structurally characterize RquA to better understand its mechanism of catalysis. We used E. coli to overexpress RquA derived from Pygsuia biforma and Rhodospirillum rubrum with a variety of fusion tags and found that RquA expresses to a high level but is located in inclusion bodies. We have developed refolding procedures to isolate RquA and are now characterizing its structure as well as the substrates required for RQ production. Support or Funding Information This research is funded by the New Frontiers in Research Fund ‐ Exploration Stream
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 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".