Rv0082 Family assigned · medium auto-curated

H37Rv Rv0082 · MTBC0 mtbc0_000092 · 159 aa · 90087–90566 MTBC0 (+) · RefSeq NP_214596.2

Genomic neighbourhood (genome browser)

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+ strand − strand glyA2 (Rv0070c) — requalified: serine hydroxymethyltransferase Rv0071 (Rv0071) — family_assigned: reverse transcriptase domain-containing protein Rv0072 (Rv0072) — family_assigned: FtsX-like permease family protein Rv0072 Rv0073 (Rv0073) — family_assigned: ATP-binding cassette domain-containing protein Rv0073 Rv0074 (Rv0074) — family_assigned: amidohydrolase family protein Rv0074 Rv0075 (Rv0075) — family_assigned: MalY/PatB family protein Rv0075 Rv0077c (Rv0077c) — family_assigned: alpha/beta hydrolase Rv0077c Rv0078 (Rv0078) — family_assigned: TetR/AcrR family transcriptional regulator Rv0079 (Rv0079) — requalified: dormancy-associated translation inhibitor Rv0080 (Rv0080) — family_assigned: pyridoxamine 5'-phosphate oxidase family protein Rv0081 (Rv0081) — family_assigned: lsr2/espR transcriptional regulator Rv0082 (Rv0082) — family_assigned: NADH-quinone oxidoreductase subunit B family protein Rv0083 (Rv0083) — requalified: oxidoreductase Rv0083 hycD (Rv0084) — family_assigned: respiratory chain complex I subunit 1 family protein hycD hycP (Rv0085) — family_assigned: hypothetical protein hycQ (Rv0086) — requalified: hydrogenase HycQ hycQ hycE (Rv0087) — family_assigned: NADH-quinone oxidoreductase subunit C hycE Rv0090 (Rv0090) — dark: DUF2127 domain-containing protein mtn (Rv0091) — requalified: 5'-methylthioadenosine/adenosylhomocysteine nucleosidase ctpA (Rv0092) — requalified: heavy metal translocating P-type ATPase ctpA 80 kb 84 kb 88 kb 92 kb 96 kb 100 kb

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)oxidoreductase
MTBC0 PGAP re-annotationNADH-quinone oxidoreductase subunit B family protein
Revised (this work)NADH-quinone oxidoreductase subunit B family protein. Pfam: Oxidored_q6 (PF01058.30).
Functional category (TubercuList)intermediary metabolism and respiration

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.

Intrinsic disorder (sequence + structure) partially disordered

Predicted disorder20% of residues (metapredict) · mean AlphaFold pLDDT 94.9
Disordered regions1 IDR(s), longest 32 aa [0-32]

carries a substantial disordered region (32/159 residues); disorder is a property, not a function

A property (biophysics), not a function. No LLPS/condensate claim is made from disorder alone. Verdict unchanged. Source: metapredict v3 (Emenecker/Holehouse) per-residue disorder + AlphaFold mean pLDDT (annotation_mtbc P16.13).

Genomic-neighbour overlap (structural caveat) co-directional · 1 % of gene

NeighbourRv0083 (Rv0083, + strand)
Overlap4 bp, 1 % of this gene's length

co-directional overlap: ordinary (e.g. shared stop/start codons in an operon), not the Rv2438A-type artefact P20.1, derived from GFF3 gene coordinates, 2026-08-03.

Conditional expression context (iModulons)

Member of 1 independently-modulated gene set(s): LysG (lsyG).

iModulon membership (independently-modulated gene sets from a 647-sample RNA-seq compendium): the conditional co-expression context. Co-expression is a regulatory context, NOT a molecular function. Source: iModulonDB / modulome_mtb (Yoo 2022).

CRISPRi vulnerability

Vulnerability index -1.95 (95% CI -10.08 to 7.00). 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; probably involved in cellular metabolism.
Mycobrowser EC 1.-.-.-

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 Mb0085 · 100.0% identity
M. marinum MMAR_1654 · 79.2% identity
M. orygis RJtmp_000092 · 100.0% 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 I6XUD2 TrEMBL · unreviewed · Evidence at protein level
UniProt nameProbable oxidoreductase

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category C Energy production and conversion
Preferred namehycG
eggNOG descriptionoxidoreductase
Orthologous groupCOG3260

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 0.193 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 1 missense, 0 nonsense, 0 frameshift

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) Bacteria

M. canettii dN/dS (deep-divergence selection) 0.0 (low power) · 6 consensus substitution(s)
low power (6 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable
Genus-wide presence (~53 non-MTBC Mycobacterium) present in 49/53 (92%) · mean identity 67.5% · 3/4 closest MTBAP relatives
conserved across the genus (present in 49/53 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 8/13 non-Mycobacterium reference genomes (down to Bacteria) · mean identity 38.9%
detected down to outside the phylum (Proteobacteria/Firmicutes controls) — a universally conserved, ancient bacterial 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) 7 in the ORF — 0 in the essential state, 0 growth-defect, 7 non-essential, 0 growth-advantage. Saturation 0.714, mean read count 53.6. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction.
CaveatRead with some caution: only 7 TA (Himar1) sites in the whole ORF (atlas median 13). The DeJesus 2017 call rests on fewer independent observations than for a longer gene. If this gene overlaps a neighbour (see Genomic-neighbour overlap section below), some of these 7 sites may fall inside the neighbour's ORF rather than its own, leaving even fewer truly informative sites than the raw count suggests. (P20.3)

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.

Mutant phenotypes (conditional Tn-seq, MtbTnDB) in-vivo phenotype

Conditionlog2FCqEffect
fitness in mouse infection (in vivo) -1.300.015 required

Conditional fitness of transposon-disruption mutants across 1 significant condition(s) (|log2FC|≥1, q≤0.05), from the standardized MtbTnDB compendium. A negative log2FC means the mutant is depleted — the gene contributes to fitness in that condition. An in-vivo defect for a "hypothetical" is strong evidence it matters for infection, even without a known molecular function. Disruption (Tn insertion), not a clean deletion; genetic-interaction screens excluded.

Proteomics (mass spectrometry) detected

MS detectiondetected in 7 of 16 independent MS datasets
Integrated abundance13.9 ppm · rank 2528/3519 (28.2th 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)

Length159 aa
Molecular weight16.3 kDa
Theoretical pI7.67
GRAVY0.37 (hydrophobic)
Aliphatic index97.5
Aromaticity0.044
Instability index37.7 (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
Oxidored_q6PF01058.30 1.2e-2845–155 NADH ubiquinone oxidoreductase, 20 Kd subunit

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 94.9

PDB hitprobTM-scoreE-valueDescription
7z0t-assembly1_G 1.00 0.96 6.2e-14 sig 7z0t-assembly1_G Structure of the Escherichia coli formate hydrogenlyase complex (aerobic preparation, composite structure)
6cfw-assembly1_J 1.00 0.90 7.5e-14 sig 6cfw-assembly1_J cryoEM structure of a respiratory membrane-bound hydrogenase
7ard-assembly1_B 1.00 0.93 9.2e-13 sig 7ard-assembly1_B Cryo-EM structure of Polytomella Complex-I (complete composition)
8e73-assembly1_S7 1.00 0.92 1.9e-12 sig 8e73-assembly1_S7 Vigna radiata supercomplex I+III2 (full bridge)
8bee-assembly1_B 1.00 0.92 6.3e-12 sig 8bee-assembly1_B Cryo-EM structure of the Arabidopsis thaliana I+III2 supercomplex (CI peripheral core)

Foldseek search of the AlphaFold DB model (mean pLDDT 94.9, 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 8

Upstream (5' on genome)Rv0081 (+ strand, 4 bp gap)
Downstream (3' on genome)Rv0083 (+ strand, -4 bp gap)
Predicted operon Rv0081 · Rv0082 · Rv0083 · hycD · hycP · hycQ · hycE · Rv0088

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).

Transcriptional regulation (signed TRN: ChIP-seq + TFOE)

Regulated by (5 TF) Rv0047c (activates) · Rv0081 (represses) · whiA (represses) · Rv1719 (activates) · Rv1985c (represses)

Regulatory edges from the ISB signed transcriptional regulatory network (TF ChIP-seq binding, Minch 2015 + TF-overexpression response, Rustad 2014). An edge is regulatory evidence (binding and/or expression change), not necessarily direct. For a "hypothetical", membership in a known regulon (e.g. DosR dormancy, PhoP virulence) is a strong physiological-context lead.

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: hycE (formate hydrogenase HycE), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0087 hycE exp formate hydrogenase HycE 999 1000 ctx neighborhood:884 cooccurence:774 coexpression:926 experimental:999 textmining:835
Rv0084 hycD exp formate hydrogenlyase HycD 999 1000 ctx neighborhood:882 cooccurence:768 coexpression:844 experimental:899
Rv0083 exp oxidoreductase 999 999 ctx neighborhood:881 cooccurence:768 coexpression:884 experimental:784
Rv0086 hycQ exp hydrogenase HycQ 998 999 ctx neighborhood:874 cooccurence:770 coexpression:840 experimental:784
Rv0085 hycP hydrogenase HycP 994 994 ctx neighborhood:874 cooccurence:736 coexpression:824
Rv3153 nuoI exp NADH-quinone oxidoreductase subunit I 986 983 ctx cooccurence:534 coexpression:633 experimental:896
Rv0081 HTH-type transcriptional regulator 985 975 ctx neighborhood:881 coexpression:800 textmining:433
Rv3148 nuoD NADH-quinone oxidoreductase subunit D 730 730 ctx cooccurence:728
Rv0088 polyketide cyclase/dehydrase 656 656 ctx neighborhood:644
Rv0080 hyp hypothetical protein 841 558 ctx neighborhood:554 textmining:655
Rv3152 nuoH NADH-quinone oxidoreductase subunit H 604 557 ctx cooccurence:518
Rv0079 hyp hypothetical protein 787 551 ctx neighborhood:548 textmining:547
Rv3156 nuoL NADH-quinone oxidoreductase subunit L 612 549 ctx cooccurence:486
Rv3158 nuoN NADH-quinone oxidoreductase subunit N 538 521 ctx cooccurence:499
Rv3157 nuoM NADH-quinone oxidoreductase subunit M 512 512 ctx cooccurence:490

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: oxidoreductase
  • MTBC0 PGAP product: NADH-quinone oxidoreductase subunit B family protein
  • Pfam (hmmscan --cut_ga): Oxidored_q6 PF01058.30 (E=1e-28)
  • (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_214596.2)
  • Domains: Pfam-A via hmmscan --cut_ga — Oxidored_q6 (PF01058.30)
  • 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 COG3260
  • Curated reference: UniProt I6XUD2 (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 94.9)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 22 functional partner(s); context anchor hycE
  • 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)
  • Transcriptional regulation: ISB signed TRN — TF ChIP-seq (Minch et al. 2015, doi:10.1038/ncomms6829) + TF overexpression (Rustad et al. 2014, doi:10.1186/gb-2014-15-11-502)
  • Mutant phenotypes: standardized Tn-seq compendium MtbTnDB (Jinich et al. 2025, doi:10.1111/mmi.15370), aggregating many primary Tn-seq studies across conditions
  • 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_000092|Rv0082|
MGWVAKIFRVGRVVEPAAPLPAAIAEPPAGVRGSLQIRHVDAGSCNGCEVEISGAFGPVYDAERFGARLVASPRHADALLVTGVVTHNMAGPLRKTLEATPRPRVVIACGDCALNRGVFADAYGVVGAVGEVVPVDVEIAGCPPTPAAIMAALRSVTGK