This guide combines the actual direct and database evidence assessments for 36 current source contexts. One absent historical location record is retained separately, preserving its source and quotation context. Source retirement describes the observed GOA boundary, not biological loss. The canonical 333-residue precursor, its 314-residue mature chain after removal of 19 residues, and the 284-residue alternative product are distinct. Individual assays do not establish equivalent function for both natural products.
This guide records actual inspected sections and target records. Human precursor 333 aa and alternative product 284 aa remain separate. Mitochondrial cleavage of 19 residues produces a 314-aa mature canonical chain, not a third splice isoform. No supporting-text quotations are added.
Read: Main Results describing the HSC20 two-hybrid screen and SDHB validation; Experimental Procedures, yeast two-hybrid/construct sections; supplementary Table S1 access attempted.
Evidence: Mature human HSC20/HSCB 29–235 served as bait against a HeLa cDNA library in yeast AH109. Main SDHB validation is distinct from the unresolved ETFA target entry.
Limits: Original main text read; exact ETFA Table S1 record not recovered. Download endpoints returned HTML proof-of-work pages, not XLSX. No ETFA-specific validation or Fe–S function inferred.
Read: Main Results defining the CFTR interaction network; Methods CoPIT, cell models, controls and confidence analysis; supplementary Tables S1–S4 access attempted.
Evidence: Human bronchial epithelial CFTR immunopurification/mass spectrometry uses CFTR-null and mock controls and includes indirect complex associations.
Limits: The exact ETFA supplementary table entry was not recovered. The main text is available but does not by itself validate this partner. No binary-contact or transporter-regulatory role assigned.
Read: Results and Figure 5B–E captions, STAR Methods/constructs, ETF/LYRM5 purification and DCIP activity assay.
Evidence: Human cell co-purification/native-complex evidence and recombinant LYRM5–ETFalpha/beta purification/size-exclusion support association. LYRM5 inhibits/deflavinates ETF. ETF is not the deflavinase.
Limits: Exact ETF construct residue/species provenance is not independently resolved by the main purification Methods. Figure captions/text were read, not figure pixels. Independent human structure supplies ETFalpha/beta interface specificity.
Read: Main Results, HSC20 interactome; STAR Methods immunoprecipitation, mitochondrial preparation and native-gel mass spectrometry; Table S1 attempted.
Evidence: Human HEK293 endogenous HSC20 immunoprecipitation with IgG control and tagged-HSC20 native-gel/MS are distinct workflows. Current IntAct has the exact HSCB–ETFA pair in anti-bait/anti-tag contexts.
Limits: Original ETFA Table S1 cells were not accessible; current curated pair does not replace them. The initial screen uses crude organelle lysates, not a demonstrated ETFA matrix-purification experiment.
Read: Main BioPlex Methods: human ORFeome clone production, 293T/HCT116 AP-MS, protein identification and interaction scoring.
Evidence: Human tagged-ORF affinity purifications provide experimental association evidence. Current IntAct contains ETFA–ETFB; the independent human ETF structure resolves its direct heterodimer interface.
Limits: No full original ETFA screen table or complete clone sequence was independently read. Protein-group inference can collapse isoforms; no current natural-product equivalence is inferred.
Read: Methods MaMTH-HTS and arrayed validation; actual Dataset EV1 Sequencing Results row4304, EV2 F508del-CFTR row102, EV4 Data row298, EV5 MaMTH Luciferase Assay row92, EV8 CFTR Interactors row152; EV7 trafficking row17.
Evidence: ETFA/ORF 535 (1002 nt recorded) is a reproducible initial mutant-CFTR screen hit. Both WT and mutant luciferase retests are explicitly Unconfirmed; the summary has no positive ETFA co-IP or significant trafficking effect.
Limits: HEK293 reporter assay with tagged CFTR/preys; exact ORF sequence not verified. Initial signal is not erased, but failed retests leave physical binding unresolved. Workbook cells, not a secondary summary, were inspected.
Read: Results and Figure3/4/EV4/EV5/6 captions; Methods GST-pull-down and proteomic workflow.
Evidence: Human HaCaT endogenous S1P–ETF association, ETFA/ETFB peptide recovery and co-IP support the interaction. ETFB has independent heterodimer support.
Limits: Figure 3D caption calls S1P in-vitro-translated, whereas Methods describe Flag-S1P lysates; no clean isolated-binary claim. A Figure 4G/Results directional discrepancy was not used. Docking is a model, not experimental structure. No pixels read.
Read: Methods/Results CFTR proximity labeling; Supplementary Table S1 APEX2 WT-control row614, TurboID WT-control row593, SAINT APEX2 row954, SAINT TurboID row716, mutant APEX2 row427, mutant TurboID row345 and KCNK3 comparison row588.
Evidence: ETFA is present in complete tables but has non-significant, negative WT-control enrichment and high SAINT FDR. The method labels proximity and does not itself establish physical binding.
Limits: Human HEK293 WT/G551D/W1282X CFTR fusion constructs; source mutant contexts retained. No universal negative interaction inferred. Table third-row header is FDR, not an assumed alternative score.
Read: Methods human U2OS AP-MS and separate multimodal/prediction methods; Data Availability NDEx AP-MS network95bc75d5-d1d1-11ee-8a40-005056ae23aa; exact ETFB569998→ETFA617814 edge629908.
Evidence: The exact published experimental AP-MS edge is recovered with stable human gene identifiers. Independent human structural evidence establishes heterodimerization.
Limits: The 511-member mitochondrial assembly and AlphaFold models are not substituted for the exact AP-MS edge. Complete clone sequences are unverified.
Read: Actual indexed original Methods Preparation of Mitochondria, Extraction and Digestion, Database Search; Results Isolation and Assessment and phosphopeptide enrichment. Normal-cache Abstract/Discussion separately read.
Evidence: Human vastus-lateralis mitochondrial isolation with functional controls and phosphoproteomics supplies study context. Independent MitoCoP and import experiments establish the target localization.
Limits: Only bounded original sections were recovered, not a full locally parsed main article. Exact ETFA supplementary phosphosite/target record remains unread. Normal full_text_available metadata overstates operative cached content and is unchanged.
Read: Main Results/Methods fractionation and importomics; actual Table S1A ETFA groups rows 346–348; S2G rows 1357/3002; S3A row 524.
Evidence: ETFA protein groups map to mitochondria in four human cell lines. This gives positive human mitochondrial evidence independent of old import studies.
Limits: Not matrix-resolved. Historical P13804-2/group masses differ across tables (35.08 versus 30.025 kDa), so no present-day 284-aa isoform assignment is made. The inspected TOMM40 ETFA-associated entry is not significant. Only selected sheets/target rows of the large supplement were inspected.
Read: Genuine normal PubMed abstract; bounded original-access routes unsuccessful.
Evidence: Human alpha precursor cloning, translation/import and rat peptide comparison are reported in the abstract. Actual1986 import/processing and 2021 human proteomics independently resolve mitochondrial location.
Limits: Original operative Methods/Results unavailable. The abstract explicitly says the mature N terminus was blocked; no exact cleavage site or natural-isoform functional equivalence inferred.
Read: JCI78, printed pp997–1002; extracted Methods/Results lines1–320; actual page images printed998–1000, Figures1–6 and surrounding text.
Evidence: Rat-liver mRNA/isolated rat mitochondria establish precursor import/processing; separate human fibroblast metabolic labeling, uncoupler inhibition and recovery establish endogenous alpha precursor processing.
Limits: No direct human matrix subfractionation, exact 19-residue cleavage measurement or identification of disease-associated short bands as the natural 284-aa product. Other image pages and supplementary material were not inspected.
Read: Genuine normal PubMed abstract; bounded Wiley/original-access attempts unsuccessful.
Evidence: The reported human beta-subunit cloning/import is compatible with matrix ETF; independent human matrix records and actual alpha precursor experiments support the ETFA location.
Limits: Main unavailable. Do not call this an independently inspected ETFA import assay or conclude citation misattribution because the abstract foregrounds ETFB.
Read: Genuine normal PubMed abstract; bounded DOI/original-access attempt unsuccessful.
Evidence: Abstract explicitly describes ETFalpha/beta as matrix components and ETFDH electron delivery, with experimental mouse mapping focus.
Limits: Main unavailable. Mouse chromosomal mapping is not a human localization assay; independent human matrix records support the location.
Read: Genuine normal PubMed abstract; ACS original full-text route returned403.
Evidence: Abstract reports human ETF flavin reconstitution, dehydrogenase/DCIP electron transfer and ETF-QO exchange. Actual 2015 and 1996 originals independently establish redox participation and alpha FAD binding.
Limits: No operative old Methods/Results access; do not treat its detailed kinetics or analogue interpretation as independently checked.
Read: Experimental Procedures human ORFs and protein purification; the recombinant ETF preparation (Δ19-ETFalpha/full-length His6-ETFbeta) and DCIP-assay subsections; Results/Figure 5 and substrate/mutant controls.
Evidence: Human untagged mature Δ19-ETFalpha plus full-length His6-ETFbeta, Δ25-MCAD or Δ44-GCDH were expressed in E. coli. Octanoyl-CoA/MCAD or glutaryl-CoA/GCDH drives ETF-dependent DCIP reduction at 600 nm. METTL20 methylates beta K200/K203 and affects transfer.
Limits: Artificial DCIP acceptor, not direct respiratory flux or reconstituted ETFDH-to-CoQ. No autonomous alpha assay; 284-aa product untested. Normal cache lacks operative sections despite availability flag; actual alternative PMC main is the operative source. Figure captions/text read, no pixels.
Read: Genuine normal PubMed abstract; Elsevier original route403.
Evidence: Abstract describes human ETFalpha variants, flavin properties and dehydrogenase/ETF-QO reactions. Actual 1996 structure and 2015 biochemical original independently resolve shared functions.
Limits: Original main inaccessible; no full mutant kinetic/construct verification is claimed.
Read: Methods recombinant human ETF/crystallography; Results Overall Structure, domains and FAD/AMP contacts; Figure 1–4 captions/text.
Evidence: Human alpha/beta cDNAs expressed in E. coli yield a 2.1-Angstrom heterodimer. Alpha C-terminal domain binds most FAD, with beta contacts near flavin; AMP resides in beta domain III.
Limits: The paper calls the first resolved alpha residue alpha Q21, second mature residue. Current P13804 has Q20/S21, so historical residue numbering is retained as paper numbering, not silently mapped onto current coordinates. The other explicitly checked contacts R223/S248/R249/Q262/Q265/T266/H286 match the current sequence, so no universal offset is inferred. No 284-aa product or isolated-alpha activity tested. No figure pixels read.
The human ETFA entity 169262 itself has compartment GO:0005759 and P13804 identity; its 1–? coordinates remain unresolved model coordinates. The UniProt SL-0170 record explicitly maps matrix location. These records supply matrix specificity independently of mitochondrial-resolution microscopy, fractionation and precursor-processing experiments. R-HSA-169260 models ETF receiving reducing equivalents; R-HSA-169270 models ETFDH reducing ubiquinone while ETF changes redox state. ETFA is not assigned ETFDH enzymatic chemistry.
Current protein heterodimerization activity is a molecular function under protein binding by is_a ancestry. It matches the experimentally resolved unlike-subunit interface. Mitochondrial matrix provides the established finer compartment.
The private read ledger distinguishes actual main originals, selected original tables, partial web-indexed sections and inaccessible material. HTML challenges, empty archives and XML error responses are never counted as recovered originals. Normal publication bytes and availability metadata remain unchanged; reviewer access flags record actual access.
The human ETF alpha subunit binds FAD and contributes electron transfer within the alpha/beta heterodimer. The evidence below distinguishes this role from ETFDH-mediated ubiquinone reduction and separates the canonical precursor, its processed chain and the 284-residue splice product.
| Source | Operative evidence and access | Scope |
|---|---|---|
| PMID:8962055, human ETF structure | Purification and Crystallization; Results describing structure tracing, the ETF fold and cofactor-binding sites; Figure 4 caption. Official original body recovered and these sections read. | Human recombinant ETF expressed in E. coli. In the 1996 paper’s numbering, alpha density begins at Q21, described as the second mature residue, and beta density extends from L4 to I255. Current P13804 has Q20/S21; this local inconsistency does not imply a universal offset, since other checked contacts match the current sequence. FAD lies predominantly in alpha domain II with defined alpha and additional beta contacts; AMP is in beta domain III. No figure pixels, supplements or raw coordinates were examined for this database assessment. |
| PMID:25416781, ETF functional assay | Experimental Procedures: cloning, recombinant ETF preparation and DCIP reduction assay; Results and Figure 5 caption, especially panels A, B and D. Official original body recovered and operative sections read. | Untagged mature human Δ19-ETFα was coexpressed with full-length His6-ETFβ in E. coli. MCAD or GCDH oxidation of octanoyl-CoA or glutaryl-CoA supplies electrons to ETF and then artificial DCIP. This is not isolated-alpha turnover, direct ETFDH/ubiquinone reduction or complete cellular respiratory flux. No figure pixels or supplements were examined in this assessment. |
| Reactome R-HSA-169260 | Actual event → catalyst 169261 → ETF:FAD complex 169267 → ETFA 169262 → P13804/reference entity 54490. | The human ETFA participant itself is in the mitochondrial matrix. The complex also contains ETFB/P38117, FAD and AMP. ETFA coordinates remain the model's unresolved 1–?; they are not a measured mature-chain boundary. |
| Reactome R-HSA-169270 | Actual reduced ETF input 169268 and oxidized ETF output 169267, each containing ETFA 169262. Catalyst 169271 instead points to ETFDH 448210/Q16134. | ETFA remains matrix-localized; ETFDH is at the inner membrane and supplies the ubiquinone-reductase chemistry. The event's mixed compartments do not assign inner-membrane localization or ETFDH catalysis to ETFA. Reactome's cited original papers were not independently read for these database assertions. |
| PANTHER PTHR43153 tree, alignment, PAINT IBD | Human leaf PTN002534683 descends from PTN000097952 for mitochondrion and PTN000097951 for electron transfer, beta-oxidation and FAD binding. Canonical alignment matches all 333 residues. Four positive target-path IBD records and no IBD NOT were recovered. | Human self-WITH is valid descendant evidence. The current electron-transfer IBD lists human P13804 alone, whereas captured GOA also lists a fly donor; the source-version difference is retained. Arabidopsis Q9C6I6, yeast Q12480, trypanosome Q384Q2 and fly Q7KN94 identities/aligned sequences and current source records were traced, but their individual original experiments were not read here. |
| HPA ETFA subcellular record, XML | Enhanced mitochondrial annotation for HPA018990, HPA018993 and HPA024089 across A-431, U-251MG and U2OS. The selected HPA018990 U-251MG and HPA018993 U2OS images were inspected. | Cytoplasmic punctate/tubular signal is compatible with mitochondria but does not resolve matrix, establish exclusivity or quantify colocalization. HPA024089 image was not inspected. Antigen sequence matches do not establish isoform-selective recognition: HPA018990 and HPA024089 antigens are retained in both products, while HPA018993 spans the deletion in the shorter product. |
| UniProt SL-0170, P13804 | Official matrix location maps to GO:0005759; the target record independently carries this location. | Matrix refinement uses these records and the explicit human Reactome participant, not subcompartment resolution inferred from HPA. UniProt's PMID:3760196 provenance is not represented as an original experiment read in this database assessment. |
| InterPro IPR001308 | Actual ETF-alpha/FixB family mappings are GO:0009055 and GO:0050660; the human match spans residues 14–332. | Human biochemical and structural evidence independently supports the mappings. The family label alone does not establish equivalence of natural products. |
| ARBA00092488 | Official endpoint returned HTTP 404 on the recorded acquisition. | No condition set or matching disjunct was reconstructed. ETF complex membership remains independently supported by the human structure and Reactome participants. |
The matrix replacement uses the current GO:0005759 definition and ancestry, which place it within mitochondrion. Neither localization nor catalytic equivalence is asserted for the 284-residue splice product solely from shared sequence, antibody recognition or an unqualified protein-group identifier. The canonical 333-residue precursor's 1–19 transit peptide and 20–333 processed chain are separate from splicing.
The four ordered core summaries retain electron transfer, alpha-subunit FAD binding, fatty-acid oxidation context and amino-acid catabolic context. The two catabolic entries are contexts of the same heterodimeric carrier activity. Electron transfer uses contributes_to_molecular_function because the assayed carrier is ETFA–ETFB. FAD binding remains a directly supported alpha-subunit activity. The seven existing core quotations remain historical evidence anchors; no new publication quotation has been inserted.
Current electron transfer activity, FAD binding, ETF complex, mitochondrial matrix, respiratory electron transport chain, acyl-CoA-dehydrogenase-dependent fatty-acid beta-oxidation and amino-acid catabolism definitions and typed ancestry were verified on 2026-10-24. No ancestor/descendant redundancy occurs among the three process terms. The 333-residue precursor and 284-residue alternative product remain distinct; neither the human crystal nor the mature Δ19-alpha assay establishes short-product equivalence. PMID:9334218 and PMID:10423253 retain their existing source-access limitations.
The retained short PMID:9334218 excerpt in the FAD-binding row describes upstream acyl-CoA dehydrogenases; it is not the evidence for alpha–FAD contacts. The actual human structure in PMID:8962055(https://pmc.ncbi.nlm.nih.gov/articles/PMC26136/?pdf=1) supplies those contacts (Results, Description of Cofactor Binding Sites, Figure 4 caption). The 1997 abstract remains useful for variant/flavin context, without a claim that its full original was read.
The short PMID:24606901 motif fragment appears in the title, abstract and Discussion. It does not identify ETFA or validate ETFA–HSCB binding. The main original supports the HSC20 screen and SDHB experiments; the exact ETFA Table S1 entry remains inaccessible. Preserving that fragment does not convert it into positive target evidence or establish an ETFA iron–sulfur function.
Archived ETFA-goa.tsv line 6 identifies ARBA:ARBA00026962 for the retired mitochondrial context. Rule identity is known; its historical conditions remain uninspected. This is distinct from fresh ARBA00092488 complex membership. The independent matrix and ETF-complex evidence is unchanged.
The restored biological summary draws on PMID:8962055 Introduction/Results (one FAD/one AMP and donor classes) and PMID:25416781 Introduction (fatty-acid, amino-acid and choline electron entry through ETF/ETFDH). These background pathway statements are distinguished from the latter paper’s actually reconstituted human MCAD/GCDH-to-DCIP reactions. The summary does not claim that those reactions themselves measured whole respiratory flux.