fadE6 Family assigned · medium auto-curated

H37Rv Rv0271c · MTBC0 mtbc0_000288 · 731 aa · 326648–328843 MTBC0 (-) · RefSeq NP_214785.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)acyl-CoA dehydrogenase FadE6
MTBC0 PGAP re-annotationacyl-CoA dehydrogenase family protein
Revised (this work)Acyl-CoA dehydrogenase family protein. Pfam: Acyl-CoA_dh_N (PF02771.22), Acyl-CoA_dh_1 (PF00441.30), Acyl-CoA_dh_2 (PF08028.17), Acyl-CoA_dh_M (PF02770.25).
Functional category (TubercuList)lipid metabolism

Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.

In the literature (TB corpus sweep) 1 publication

1 TB publication mentions this gene. 1 publication(s) discuss this gene (0 in a M. tuberculosis context).

PublicationDate
A Mycobacterium avium subsp. paratuberculosis LuxR regulates cell envelope and virulence. doi:10.1177/1753425909339811 2010

This layer CITES the literature and adds context; it does not change the verdict or the function stated elsewhere in this fiche. This distinguishes a gene that is dark because nobody has looked from one that is dark despite having been studied. Source: PubMed (whole): H37Rv locus tag + GENE NAME + ortholog identifiers (Mb…, MMAR_…, MSMEG_…, ML…, MAB_…), under a mycobacterial context filter; hits verified against the abstract text. Species-context counts distinguish M. tuberculosis literature from literature on other mycobacteria. phase76/phase77, 2026-07-13.

CRISPRi vulnerability

Vulnerability index 1.30 (95% CI -0.36 to 4.09). A more negative index = more vulnerable to knockdown (better drug-target quality); indicative threshold VI ≤ -6 = highly vulnerable.

Quantitative CRISPRi knockdown, graded (finer than binary Tn-seq essentiality). Source: CRISPRi vulnerability index (Bosch 2021, pebble.rockefeller.edu).

Legacy record & comparison (Mycobrowser)

Mycobrowser functionFunction unknown, but involved in lipid degradation.
Mycobrowser EC 1.3.99.-

The legacy Mycobrowser record is shown for verification. Mycobrowser is no longer maintained; its EC numbers predate recent nomenclature revisions, so a class change usually reflects re-numbering, not a conflict.

Orthologues (reciprocal best hits across mycobacteria)

M. bovis Mb0277c · 100.0% identity
M. marinum MMAR_0530 · 86.3% identity
M. smegmatis MSMEG_0603 · 79.5% identity
M. orygis RJtmp_000287 · 100.0% identity
M. abscessus MAB_4336 · 69.8% identity

Reciprocal-best-hit orthologues (DIAMOND) against the Mycobrowser reference proteomes. A missing species is informative: e.g. a gene absent from M. leprae was likely lost in its reductive genome evolution. Locus tags link to Mycobrowser.

Curated reference (UniProt)

UniProt P95228 TrEMBL · unreviewed · Evidence at protein level
UniProt nameProbable acyl-CoA dehydrogenase FadE6

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category I Lipid transport and metabolism
Preferred namefadE6
eggNOG descriptionacyl-CoA dehydrogenase
Orthologous groupCOG1960

Orthology-based transfer (eggNOG 5.0.2, diamond). EC/KO/GO/CAZy are computed annotations, not manual curation; cross-check against the primary literature before treating a specific reaction as established.

Conservation & selection (intra-MTBC, 145 209 strains)

pN/pS 0.294 · purifying
Polymorphic sites (≥ 0.1% of strains) 12 synonymous, 10 missense, 0 nonsense, 1 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 0.94% of strains (1362) · clonal

pN/pS from segregating SNPs (singletons removed) normalised by possible sites. Low pN/pS = purifying selection (a strong signal that a "hypothetical" is a real, constrained gene). A high pN/pS is ambiguous: relaxed constraint or positive selection (drug resistance, antigenic variation) inflate it; e.g. rpoB/katG/pncA score high here for resistance, not loss of function. A clonal disruption (one allele over a clade) suggests lineage pseudogenisation; a convergent one (many independent alleles) is typical of resistance loss-of-function.

Outgroup conservation (beyond the MTBC) Corynebacteriales

M. canettii dN/dS (deep-divergence selection) 0.176 (low power) · 3 consensus substitution(s)
low power (3 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable
Genus-wide presence (~53 non-MTBC Mycobacterium) present in 53/53 (100%) · mean identity 83.2% · 4/4 closest MTBAP relatives
conserved across the genus (present in 53/53 non-MTBC Mycobacterium genomes, incl. distant relatives) — an ancient core gene predating the genus radiation
Phylostratum (deepest detected homolog) MTBC-specific Mycobacterium Mycobacteriaceae Corynebacteriales Actinomycetia Bacteria
detected in 5/13 non-Mycobacterium reference genomes (down to Corynebacteriales) · mean identity 45.3%
detected across the order Corynebacteriales (Corynebacterium/Nocardia/Rhodococcus/…) but not in more distant Actinomycetia — a Corynebacteriales-level gene

Two orthogonal outgroup signals. M. canettii (the immediate outgroup) gives a deep-divergence dN/dS (a low value confirms a constrained, real gene; shown as confident only at ≥8 substitutions, else flagged low-power). Genus-wide presence/absence (tblastn vs assembled non-MTBC genomes) places the gene on the ancient-core ↔ MTBC-specific axis: a gene absent even from the closest MTBAP relatives is a candidate MTBC-specific innovation (possible host-adaptation factor, to confirm by synteny). The phylostratum extends that axis outside the genus (tblastn vs 13 reference genomes spanning Mycobacteriaceae → Corynebacteriales → Actinomycetia → outside the phylum): it is the deepest clade in which a homolog is still detected, i.e. a proxy for gene age. Read it with the null model in mind: a shallow (young) stratum can also reflect homology-detection failure for short or fast-evolving ORFs, so it is a descriptive axis, not a proof of novelty.

Essentiality (transposon mutagenesis)

DeJesus 2017 callNE · non-essential
What the call meansnon-essential
TA sites (Himar1) 35 in the ORF — 0 in the essential state, 0 growth-defect, 35 non-essential, 0 growth-advantage. Saturation 0.971, mean read count 104. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction.

Genome-wide Himar1 transposon essentiality in H37Rv (DeJesus 2017). An essential call (ES/ESD/GD) is strong, independent evidence that a "hypothetical" locus encodes a functional, selectively required gene — orthogonal to intra-species conservation.

Proteomics (mass spectrometry) detected

MS detectiondetected in 15 of 16 independent MS datasets
Integrated abundance294.0 ppm · rank 651/3519 (81.5th percentile)

Detection by mass spectrometry is direct, experimental evidence that the protein product exists — orthogonal to sequence conservation and to Tn-seq essentiality, and especially decisive for a "hypothetical" locus. Reproducible detection across several independent datasets (PaxDb) makes the existence claim robust; the integrated abundance places the protein in the proteome's dynamic range.

Physico-chemical properties (computed, ProtParam)

Length731 aa
Molecular weight78.5 kDa
Theoretical pI5.27
GRAVY0.018 (hydrophobic)
Aliphatic index94.2
Aromaticity0.074
Instability index32.0 (stable)

Computed from the ancestral MTBC0 sequence with the ExPASy ProtParam method (Biopython). Descriptive biophysical context: a positive GRAVY flags a hydrophobic (often membrane) protein, a high instability index (>40) predicts a short in-vitro half-life, an extreme pI hints at compartment or binding partner.

Domains (Pfam, hmmscan --cut_ga)

PfamAccessioni-EvalueResiduesDescription
Acyl-CoA_dh_NPF02771.22 4.5e-106–112 Acyl-CoA dehydrogenase, N-terminal domain
Acyl-CoA_dh_1PF00441.30 8.9e-25217–340 Acyl-CoA dehydrogenase, C-terminal domain
Acyl-CoA_dh_2PF08028.17 1.6e-08218–321 Acyl-CoA dehydrogenase, C-terminal domain
Acyl-CoA_dh_MPF02770.25 5.8e-18469–561 Acyl-CoA dehydrogenase, middle domain

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 93.5

PDB hitprobTM-scoreE-valueDescription
6wy8-assembly1_D 1.00 0.77 4.5e-19 sig 6wy8-assembly1_D Tcur3481-Tcur3483 steroid ACAD
6wy9-assembly1_A-2 1.00 0.74 8.8e-19 sig 6wy9-assembly1_A-2 Tcur3481-Tcur3483 steroid ACAD G363A variant
4x28-assembly1_B 1.00 0.73 1.1e-18 sig 4x28-assembly1_B Crystal structure of the ChsE4-ChsE5 complex from Mycobacterium tuberculosis
4x28-assembly1_A 1.00 0.73 1.8e-18 sig 4x28-assembly1_A Crystal structure of the ChsE4-ChsE5 complex from Mycobacterium tuberculosis
8hk0-assembly1_A 1.00 0.73 2.6e-17 sig 8hk0-assembly1_A Crystal structure of Fic32-33 complex from Streptomyces ficellus NRRL 8067

Foldseek search of the AlphaFold DB model (mean pLDDT 93.5, gated at 70) against the PDB — a genome-wide extension of the ESMFold dark-gene search that also covers proteins beyond the single-sequence length limit. Confident structural neighbours (E < 0.01) shown.

Genomic context (neighbours & predicted operon)

Upstream (5' on genome)fadD2 (+ strand, 16 bp gap)
Downstream (3' on genome)Rv0272c (- strand, 113 bp gap)

Neighbours from the H37Rv annotation (- strand). The operon is predicted by co-directional intergenic distance (same strand, gaps ≤50 bp) — a transcription-unit hypothesis, not a mapped TSS. For a "hypothetical", co-transcription with a characterised operon is a concrete functional lead (complements the STRING neighborhood channel below).

Functional interaction network (STRING v12, guilt-by-association)

Explore full network →

Node colour = verdict, dashed = hypothetical; edge colour = evidence (green experimental, orange genomic-context, grey co-expression), width ∝ score. Click a partner to open its page; "Explore full network" to walk the graph.

Closest characterised functional partner: Rv0273c (transcriptional regulator), high confidence from genomic context alone (score 785 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0272c hyp hypothetical protein 802 802 ctx neighborhood:757
Rv0860 fadB fatty oxidation protein FadB 804 789 coexpression:650
Rv0273c transcriptional regulator 785 785 ctx neighborhood:715
Rv3541c chsH1 hyp hypothetical protein 770 762 ctx cooccurence:549
Rv3029c fixA exp electron transfer flavoprotein subunit beta 733 716 coexpression:408 experimental:418
Rv3028c fixB exp electron transfer flavoprotein subunit alpha 722 711 coexpression:412 experimental:419
Rv3522 ltp4 lipid transfer protein 712 702 ctx cooccurence:498
Rv0274 hyp hypothetical protein 685 673 ctx neighborhood:544
Rv3550 echA20 enoyl-CoA hydratase EchA20 682 670
Rv3540c ltp2 lipid transfer protein 678 667 ctx cooccurence:431
Rv3523 ltp3 lipid carrier protein 677 666 ctx cooccurence:433
Rv3153 nuoI NADH-quinone oxidoreductase subunit I 651 637
Rv3538 dehydrogenase 628 628
Rv3548c short-chain type dehydrogenase/reductase 614 601
Rv3509c ilvX exp acetohydroxyacid synthase large subunit 607 601 database:407

STRING combines evidence channels (neighborhood, fusion, cooccurrence, coexpression, experimental, database, text-mining) into a 0–1000 score. The ctx badge marks edges carried by the genomic-context channels (conserved neighborhood, fusion, phylogenetic co-occurrence), which are independent of orthology and structure and the strongest signal for an unknown gene. The exp badge marks an experimentally-supported partner (measured interaction, experimental/database channel ≥400) as opposed to a purely predicted one — but note that the M. tuberculosis experimental interactome is dominated by a noisy bacterial-two-hybrid screen, so a strong measured link that contradicts the operon/localisation context is likely a false positive. The no text-mining column recomputes the score from data alone, so a link that does not depend on the literature is visible. Association is a function hypothesis, not proof: corroborate with the operon context and the primary literature before assigning a function.

Evidence

  • Legacy H37Rv annotation: acyl-CoA dehydrogenase FadE6
  • MTBC0 PGAP product: acyl-CoA dehydrogenase family protein
  • Pfam (hmmscan --cut_ga): Acyl-CoA_dh_N PF02771.22 (E=4e-10), Acyl-CoA_dh_1 PF00441.30 (E=9e-25), Acyl-CoA_dh_2 PF08028.17 (E=2e-08), Acyl-CoA_dh_M PF02770.25 (E=6e-18)
  • (auto-curated by rules from PGAP + Pfam + Foldseek; not hand-reviewed)

Sources

  • Ancestral sequence & coordinates: Harrison LB et al. (2024), An imputed ancestral reference genome for the MTBC, doi:10.1101/2023.09.07.556366
  • Product annotation: NCBI PGAP on MTBC0; legacy from H37Rv NC_000962.3 (RefSeq NP_214785.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Acyl-CoA_dh_N (PF02771.22), Acyl-CoA_dh_1 (PF00441.30), Acyl-CoA_dh_2 (PF08028.17), Acyl-CoA_dh_M (PF02770.25)
  • Sequence-level signal: ESM Atlas (EvolutionaryScale × BioHub) — exploratory
  • Controlled vocabulary: eggNOG-mapper 2.1.12 (Cantalapiedra et al. 2021, doi:10.1093/molbev/msab293), eggNOG 5.0 DB (Huerta-Cepas et al. 2019) — OG COG1960
  • Curated reference: UniProt P95228 (TrEMBL, unreviewed; Evidence at protein level)
  • Intra-MTBC selection: pN/pS and disruption from SPDI variants of 145 209 MTBC strains (this work, local collection vs H37Rv NC_000962.3)
  • Genome-wide structure: AlphaFold DB model (Jumper et al. 2021, doi:10.1038/s41586-021-03819-2; Varadi et al. 2024, doi:10.1093/nar/gkad1011) searched vs PDB with Foldseek (mean pLDDT 93.5)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 127 functional partner(s); context anchor Rv0273c
  • Essentiality: genome-wide transposon mutagenesis in H37Rv — DeJesus et al. 2017 (mBio, doi:10.1128/mBio.02133-16, CC BY)
  • Proteomics: integrated mass-spectrometry abundance from PaxDb 5.0 (Huang et al. 2023, doi:10.1016/j.mcpro.2023.100640), taxon 83332 — weighted average of 16 datasets, incl. Schubert et al. 2013 (doi:10.1016/j.chom.2013.04.008) and Albrethsen et al. 2013 (doi:10.1074/mcp.M112.018846)
  • Functional category: TubercuList scheme (Cole et al. 1998, doi:10.1038/31159), via Mycobrowser (Kapopoulou et al. 2011, doi:10.1016/j.tube.2010.09.006)
  • Orthologues: reciprocal best hits (DIAMOND, Buchfink et al. 2021, doi:10.1038/s41592-021-01101-x) against Mycobrowser release 5 reference proteomes
  • Genomic context / operon: H37Rv annotation; operon predicted by co-directional intergenic distance (Salgado et al. 2000, doi:10.1073/pnas.030539397)
  • Physico-chemical properties: ExPASy ProtParam method via Biopython (Gasteiger et al. 2005), computed from the MTBC0 sequence
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000288|Rv0271c|fadE6
MSIAITPEHYELADSVRSLVARVAPSEVLHAALESPVENPPPYWQAAAEQGLQGVHLAESVGGQGFGILELAVVLAEFGYGAVPGPFVPSAIASALIAAHDPQAKVLAELATGAAIAAYALDSGLTATRHGDVLVIRGEVRAVPAAAQASVLVLPVAIESRDEWVVLRNDQLEIEAVKSLDPLRPIAHVRANAVDVSDDALLSNLTMTTAHALMSTLLSAEAVGVARWATDTASAYAKIREQFGRPIGQFQAIKHKCAEMIADTERATAAVWDAARALDDAGESSSDVEFAAAVAATLAPATAQRCTQDCIQVHGGIGFTWEHDTNVYYRRALMLAACFGRGSEYPQRVVDTATTAGMRPVDIDLDPSTEKLRAQIRAEVAALKAMPREPRTVAIAEGGWVLPYLPKPWGRAASPVEQIIIAQEFTAGRVKRPQIAIATWIVPSIVAFGTDNQKQRLLPPTFRGDIFWCQLFSEPGAGSDLASLATKATRVDGGWRITGQKIWTTGAQYSQWGALLARTDPSAPKHNGITYFLLDMKSEGVQVKPLRELTGKEFFNTVYLDDVFVPDELVLGEVNRGWEVSRNTLTAERVSIGGSDSTFLPTLGEFVDFVRDYRFEGQFDQVARHRAGQLIAEGHATKLLNLRSTLLTLAGGDPMAPAAISKLLSMRTGQGYAEFAVSSFGTDAVIGDTERLPGKWGEYLLASRATTIYGGTSEVQLNIIAERLLGLPRDP