Component
Shewanella oneidensis MR-1 urocanate reductase / UrdA
Context-specific entity; species, compartment and exposure are stated on each claim.
2 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
What it acts on
Full-length and two-domain S. oneidensis UrdA converted urocanate to imidazole propionate and did not show the tested fumarate-reductase activity.
Experimental context and source evidence
- evidence_access
- Primary full text
- experimental_model
- Purified bacterial full-length/truncated proteins, activity assays and ligand-bound crystal structures.
- limitations
- This species is a structural model; abundance or flux in an individual human microbiome is not measured.
- nutrient_topic
- L-Histidine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Histidine
- plain_language
- A bacterial enzyme sends a histidine-derived intermediate down a different branch.
- primary_references
- Structural characterization of the microbial enzyme urocanate reductase mediating imidazole propionate production. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33649331/ · DOI 10.1038/s41467-021-21548-y
L-Histidine: supply, catabolism, histamine, receptors and cross-nutrient mechanisms (2026-09-19) · lines 266–272
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Purified bacterial full-length/truncated proteins, activity assays and ligand-bound crystal structures. · source_derived_draft · unverified_draft
## histidine-urda-product A bacterial enzyme sends a histidine-derived intermediate down a different branch. Full-length and two-domain S. oneidensis UrdA converted urocanate to imidazole propionate and did not show the tested fumarate-reductase activity. Model: Purified bacterial full-length/truncated proteins, activity assays and ligand-bound crystal structures. Limitations: This species is a structural model; abundance or flux in an individual human microbiome is not measured. Evidence access: Primary full text Structural characterization of the microbial enzyme urocanate reductase mediating imidazole propionate production. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33649331/ · DOI 10.1038/s41467-021-21548-y
Complete structured claim and evidence
What acts on it
The UrdA catalytic-domain structures contained FAD alongside substrate or product, and assays supported flavin-associated urocanate reduction.
Experimental context and source evidence
- evidence_access
- Primary full text
- experimental_model
- Bacterial structural enzymology; FAD-supplemented enzyme assays.
- limitations
- Does not show that human riboflavin intake limits or increases microbial imidazole-propionate production.
- nutrient_topic
- L-Histidine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Histidine
- plain_language
- This microbial reaction uses a riboflavin-derived chemical tool.
- primary_references
- Structural characterization of the microbial enzyme urocanate reductase mediating imidazole propionate production. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33649331/ · DOI 10.1038/s41467-021-21548-y
L-Histidine: supply, catabolism, histamine, receptors and cross-nutrient mechanisms (2026-09-19) · lines 274–280
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Bacterial structural enzymology; FAD-supplemented enzyme assays. · source_derived_draft · unverified_draft
## histidine-urda-flavin This microbial reaction uses a riboflavin-derived chemical tool. The UrdA catalytic-domain structures contained FAD alongside substrate or product, and assays supported flavin-associated urocanate reduction. Model: Bacterial structural enzymology; FAD-supplemented enzyme assays. Limitations: Does not show that human riboflavin intake limits or increases microbial imidazole-propionate production. Evidence access: Primary full text Structural characterization of the microbial enzyme urocanate reductase mediating imidazole propionate production. · 2021 · https://pubmed.ncbi.nlm.nih.gov/33649331/ · DOI 10.1038/s41467-021-21548-y
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.