Human ETHE1 directly oxidizes glutathione persulfide using oxygen. The recombinant enzyme studies support iron binding, GSSH-dependent oxygen consumption and sulfite formation; the confirming mass spectrum in the 2012 study is reported as data not shown. Free glutathione is not the assayed substrate. This supports an executed step in glutathione-conjugate and sulfide metabolism without assigning ETHE1 the upstream initial oxidation of H2S or downstream sulfate formation. See the source guide for original Methods/Results and assay boundaries.
The human preparations differ: reported Δ11/C-terminal His6 protein is monomeric by gel filtration, while GPVD plus residues 21–254 is predominantly dimeric in the later study. Native residue-8 processing, those engineered deletions and the natural internal-deletion RefSeq records are separate. A universal oligomeric state or equivalent activity of every shorter product is not established.
Native human fibroblast protease protection and soluble submitochondrial fractionation support the matrix. MitoCoP independently identifies a mitochondrial protein group but calls it peripheral membrane-associated under its carbonate/sonication conditions; that result is not relabeled as soluble-matrix proteomics. The reported nuclear signal is antibody-dependent: HPA029029 supports a bounded non-core context, while two enhanced antibodies and the aggregate HPA assessment favor mitochondria. Its shared antigen does not identify a product. The older HSCO original remains inaccessible beyond abstract/metadata, and neither shuttling nor an expression artifact is established here.
The current Reactome human ETHE1 protein has its own matrix compartment. Its parent catalyst complex separately contains two zinc components, conflicting with measured mono-iron human preparations. A probable, unreported source-composition query records this discrepancy without invalidating the matrix location or editing the source cache.
Five HuRI pairs, including self, support bounded associations of human ORFs tested in yeast. They do not establish endogenous complexes, a unique function for each interaction, or equivalence of all natural sequence records.
Glutathione persulfide is the chemically transformed substrate: purified human ETHE1 consumes oxygen and produces sulfite in the matched enzyme assay. The same step is therefore both glutathione-conjugate metabolism and a component of sulfide oxidation. It does not assign ETHE1 the initial oxidation of free H2S or the downstream production of sulfate. The measured iron center is part of this catalytic mechanism; no separate binding or self-association mechanism is needed to describe it.
The catalytic and localization evidence comes from distinct experiments. PMID:23144459 used an engineered Δ11/C-terminal His6 preparation, whereas PMID:25596185 used the GPVD-plus-21–254 preparation. PMID:14732903 supplies native human mitochondrial protection and soluble-fraction evidence. Their combination supports the matrix reaction without asserting activity of every shorter sequence record, a compulsory dimer, or a nuclear enzymatic role. Metal occupancy, expressed shorter products and antibody-specific nuclear signal remain useful targets for the proposed experiments.
Final canonical validation passes all six checks, and all 62 authored narratives appear in the private rendering. Computed DRAFT retains 4 advisories. All 27 current source contexts and 15 reference identities remain preserved; no NEW annotation or quotation is introduced. The ten selected citation/PAINT normal dependencies and two genuine gene machine files remain exact, as do all 19 private normal dependencies and eight unrelated baseline paths.
Retain the historical PMID:12398897 experimental cytoplasm annotation as non-core alongside its nuclear observation. The full original remains unavailable; separate native-human matrix evidence does not erase the earlier possible extra-mitochondrial context. Other location refinements continue to use their explicitly identified independent evidence.
The UniProt record, CC:SUBUNIT, curates association with TST (PMID:19136963). Newly read portions of the already recovered main original report ETHE1-HA/rhodanese co-immunoprecipitation in HeLa and human rhodanese-His6 expression. No supplementary panels were inspected. This is positive cellular association, not purified binding or an endogenous substrate-channeling demonstration. The original discussion and PMID:23144459 place rhodanese downstream in the discussed pathway and consider alternative sulfur flows; they do not establish an obligatory immediately upstream TST step. A focused question preserves the unresolved native coupling.
CC:COFACTOR and CC:SUBUNIT are cited from the unchanged normal record; the source guide gives exact section and public original/Reactome locators. Iron coordination is explicitly part of the single catalytic core. No new annotation or publication quotation is introduced, consistent with the campaign instructions. The actual record-section backfill is tested privately; it derives sections only for verbatim quotation objects, so this reference-only, zero-quote revision does not invent record_section metadata.
The existing GO:0019418 process is retained; the sulfide-term consolidation project documents the retired mechanism-specific terms. No project inventory or external ontology issue is modified. The description now names ethylmalonic encephalopathy as biological context. Repeated construct/fractionation paragraphs are centralized in the source guide, while row-specific evidence and access limits remain. The revised actions are 13 ACCEPT, 6 MODIFY and 8 KEEP_AS_NON_CORE across the same 27 source contexts.
Private revision validation passes normal validation, strict terms, whole/component schemas and strict GOA alignment, with all selected normal sources unchanged. It reports five advisories: the four documented binding cases and the deliberate historical-cytoplasm versus independent-matrix context distinction. The prior canonical-validation paragraph above records the earlier published checkpoint; canonical revision validation and new history remain a subsequent step.
The revised canonical review passes all six checks; all 63 narrative strings appear in the private rendering. Computed status is DRAFT with 5 advisories, including the deliberate historical-cytoplasm versus independent matrix-refinement distinction and generic-binding policy. All 27 source contexts, 15 original reference identities, one added unchanged-record reference, one catalytic core and zero quotations are preserved. Normal source files and the prior history record remain unchanged.