Rv0785 Resolved · high auto-curated

H37Rv Rv0785 · MTBC0 mtbc0_000835 · 566 aa · 883766–885466 MTBC0 (+) · RefSeq NP_215299.1

Genomic neighbourhood (genome browser)

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This gene (outlined) in its genomic context; arrows are neighbouring genes coloured by verdict. Click any gene to navigate. Pan and zoom in the full browser.

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)KsdD-like steroid dehydrogenase
MTBC0 PGAP re-annotationFAD-binding dehydrogenase
Revised (this work)FAD-binding dehydrogenase. Pfam: FAD_binding_3 (PF01494.26), FAD_binding_2 (PF00890.31), NAD_binding_8 (PF13450.13).
Functional category (TubercuList)conserved hypotheticals

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) never studied

No publication mentions this gene in its title or abstract — not under its H37Rv locus tag, not under its gene name, and not under any ortholog identifier. Its annotation rests on sequence/structure evidence, with no primary study behind it.

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 0.73 (95% CI -2.13 to 4.59). 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) ahead of Mycobrowser

Mycobrowser functionFunction unknown

Mycobrowser classes this locus among conserved hypotheticals; the atlas now assigns a functional handle (curated function (UniProt), EC number, requalified function). Mycobrowser is no longer maintained, so its EC numbers predate recent nomenclature revisions (e.g. the 2018 EC 7 "translocase" class) — most EC differences are re-numberings of the same enzyme, not conflicts.

Orthologues (reciprocal best hits across mycobacteria)

M. bovis Mb0808 · 99.5% identity
M. marinum MMAR_4632 · 60.9% identity
M. smegmatis MSMEG_5835 · 79.4% identity
M. abscessus MAB_0695 · 77.1% 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 P71838 SwissProt · reviewed · Evidence at protein level
UniProt nameKsdD-like steroid dehydrogenase Rv0785
EC (curated) EC 1.3.99.-
Curated functionAble to catalyze the elimination of the C-1 and C-2 hydrogen atoms of the A-ring from the polycyclic ring structure of 3-ketosteroids.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
eggNOG descriptionDehydrogenase
Orthologous groupCOG3573
KEGG orthology K07077
Gene Ontology (25) GO:0003674, GO:0003824, GO:0005575, GO:0005623, GO:0005886, GO:0006629, GO:0006694, GO:0008150, GO:0008152, GO:0008202, GO:0008610, GO:0009058 +13 more

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) pseudogene candidate

pN/pS 0.573 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 3 synonymous, 5 missense, 0 nonsense, 1 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 11.99% of strains (17405) · 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) Actinomycetia

M. canettii dN/dS (deep-divergence selection) 0.344 (low power) · 7 consensus substitution(s)
low power (7 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable
Genus-wide presence (~53 non-MTBC Mycobacterium) present in 52/53 (98%) · mean identity 81.4% · 4/4 closest MTBAP relatives
conserved across the genus (present in 52/53 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 6/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 66.2%
detected across the class Actinomycetia (beyond Corynebacteriales) but not outside the phylum — an Actinobacteria-level ancient 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) 36 in the ORF — 0 in the essential state, 0 growth-defect, 36 non-essential, 0 growth-advantage. Saturation 0.861, mean read count 61.2258064516. 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 12 of 16 independent MS datasets
Integrated abundance40.9 ppm · rank 1888/3519 (46.4th 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.

Predicted localisation (DeepTMHMM + lipobox) lipoprotein

Predictionpredicted lipoprotein (lipobox + signal peptide)
DeepTMHMM classGLOB
Lipoboxsignal-peptidase-II lipobox; lipidated Cys near position 38

Transmembrane topology and signal peptide from DeepTMHMM (deep-learning reference predictor); lipoproteins from a (myco)bacterial lipobox motif. A sequence-based prediction of subcellular context.

Physico-chemical properties (computed, ProtParam)

Length566 aa
Molecular weight61.3 kDa
Theoretical pI9.2
GRAVY-0.189 (hydrophilic)
Aliphatic index88.8
Aromaticity0.08
Instability index31.0 (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
FAD_binding_3PF01494.26 1.6e-0522–62 FAD binding domain
FAD_binding_2PF00890.31 2.0e-8823–547 FAD binding domain
NAD_binding_8PF13450.13 2.0e-0826–62 NAD(P)-binding Rossmann-like domain

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 93.4

PDB hitprobTM-scoreE-valueDescription
6t85-assembly1_A 1.00 0.78 7.4e-31 sig 6t85-assembly1_A Urocanate reductase in complex with ADP
4c3x-assembly2_F 1.00 0.73 1.1e-29 sig 4c3x-assembly2_F Crystal structure of 3-ketosteroid delta1-dehydrogenase from Rhodococcus erythropolis SQ1
4c3y-assembly2_H 1.00 0.71 5.2e-30 sig 4c3y-assembly2_H Crystal structure of 3-ketosteroid delta1-dehydrogenase from Rhodococcus erythropolis SQ1 in complex with 1,4-androstadiene-3,17- dione
2b7s-assembly1_A 1.00 0.66 1.5e-28 sig 2b7s-assembly1_A R381K mutant of flavocytochrome c3
1kss-assembly1_A 1.00 0.65 8.3e-29 sig 1kss-assembly1_A Crystal Structure of His505Ala Mutant Flavocytochrome c3 from Shewanella frigidimarina

Foldseek search of the AlphaFold DB model (mean pLDDT 93.4, 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) operon of 2

Upstream (5' on genome)Rv0784 (+ strand, 15 bp gap)
Downstream (3' on genome)Rv0786c (- strand, 34 bp gap)
Predicted operon Rv0784 · Rv0785

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: emrB (multidrug resistance protein EmrB), high confidence from genomic context alone (score 727 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0784 hyp hypothetical protein 863 864 ctx neighborhood:863
Rv0783c emrB multidrug resistance protein EmrB 726 727 ctx neighborhood:723
Rv1769 hyp hypothetical protein 443 444 ctx cooccurence:442

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: KsdD-like steroid dehydrogenase
  • MTBC0 PGAP product: FAD-binding dehydrogenase
  • Pfam (hmmscan --cut_ga): FAD_binding_3 PF01494.26 (E=2e-05), FAD_binding_2 PF00890.31 (E=2e-88), NAD_binding_8 PF13450.13 (E=2e-08)
  • (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_215299.1)
  • Domains: Pfam-A via hmmscan --cut_ga — FAD_binding_3 (PF01494.26), FAD_binding_2 (PF00890.31), NAD_binding_8 (PF13450.13)
  • 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 COG3573
  • Curated reference: UniProt P71838 (SwissProt, reviewed; 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 93.4)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 3 functional partner(s); context anchor emrB
  • 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
  • Predicted localisation: DeepTMHMM (Hallgren et al. 2022, doi:10.1101/2022.04.08.487609) for transmembrane topology and signal peptide; (myco)bacterial lipobox (Sutcliffe & Harrington 2004, doi:10.1099/mic.0.26804-0)
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000835|Rv0785|
MALTCTDMSDAVAGSDAEGLTADAIVVGAGLAGLVAACELADRGLRVLILDQENRANVGGQAFWSFGGLFLVNSPEQRRLGIRDSHELALQDWLGTAAFDRPEDYWPEQWAHAYVDFAAGEKRSWLRARGLKIFPLVGWAERGGYDAQGHGNSVPRFHITWGTGPALVDIFVRQLRDRPTVRFAHRHQVDKLIVEGNAVTGVRGTVLEPSDEPRGAPSSRKSVGKFEFRASAVIVASGGIGGNHELVRKNWPRRMGRIPKQLLSGVPAHVDGRMIGIAQKAGAAVINPDRMWHYTEGITNYDPIWPRHGIRIIPGPSSLWLDAAGKRLPVPLFPGFDTLGTLEYITKSGHDYTWFVLNAKIIEKEFALSGQEQNPDLTGRRLGQLLRSRAHAGPPGPVQAFIDRGVDFVHANSLRELVAAMNELPDVVPLDYETVAAAVTARDREVVNKYSKDGQITAIRAARRYRGDRFGRVVAPHRLTDPKAGPLIAVKLHILTRKTLGGIETDLDARVLKADGTPLAGLYAAGEVAGFGGGGVHGYRALEGTFLGGCIFSGRAAGRGAAEDIR