Rv1176c Family assigned · medium auto-curated

H37Rv Rv1176c · MTBC0 mtbc0_001265 · 189 aa · 1316664–1317233 MTBC0 (-) · RefSeq NP_215692.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationPadR family transcriptional regulator
Revised (this work)PadR family transcriptional regulator. Pfam: PadR (PF03551.21), Vir_act_alpha_C (PF10400.16).
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) 2 publications

Found under: H37Rv (2).

2 TB publications mention this gene. 2 publication(s) mention this gene (title/abstract), verified against the text. The atlas states the function; these are the primary sources that discuss it.

PublicationDate
Structural and biophysical characterization of PadR family protein Rv1176c of Mycobacterium tuberculosis H37Rv. doi:10.1016/j.ijbiomac.2024.130455 2024
Computational Identification of the Proteins Associated With Quorum Sensing and Biofilm Formation in Mycobacterium tuberculosis. doi:10.3389/fmicb.2019.03011 2019

This layer CITES the literature, it does not change the verdict or the function. A gene may be heavily studied (as an antigen, a resistance determinant, a drug target) while its molecular function is settled elsewhere in the fiche. This distinguishes a gene that is dark because nobody has looked from one that is dark despite having been studied. Source: PubMed (whole), MULTI-ALIAS sweep: H37Rv locus tag AND every ortholog identifier (M. bovis Mb…, M. marinum MMAR_…, M. smegmatis MSMEG_…, M. leprae ML…, M. abscessus MAB_…), each hit VERIFIED against the abstract text (word-boundary regex). phase73/phase75, 2026-07-13.

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

NeighbourfadH (Rv1175c, - 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.

CRISPRi vulnerability

Vulnerability index 0.38 (95% CI -0.33 to 1.37). 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), COG category). 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 Mb1209c · 100.0% identity
M. marinum MMAR_4275 · 80.9% identity
M. smegmatis MSMEG_6605 · 32.6% identity
M. orygis RJtmp_001241 · 100.0% identity
M. abscessus MAB_1326c · 53.0% 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 O50432 SwissProt · reviewed · Evidence at protein level
UniProt nameProbable transcriptional regulator Rv1176c
Curated functionProbable transcriptional regulator that may help mitigate the effect of oxidative stress and help mycobacteria survive inside macrophages. Binds to its own promoter region.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category K Transcription
Preferred namepadR
eggNOG descriptionVirulence activator alpha C-term
Orthologous groupCOG1695

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 0.672 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 2 missense, 0 nonsense, 1 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 0.79% of strains (1149) · 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

Genus-wide presence (~53 non-MTBC Mycobacterium) present in 38/53 (72%) · mean identity 53.6% · 3/4 closest MTBAP relatives
conserved across the genus (present in 38/53 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 50.4%
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) 15 in the ORF — 0 in the essential state, 0 growth-defect, 15 non-essential, 0 growth-advantage. Saturation 0.867, mean read count 108. 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 7 of 16 independent MS datasets
Integrated abundance7.25 ppm · rank 2801/3519 (20.4th 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.

Physico-chemical properties (computed, ProtParam)

Length189 aa
Molecular weight21.1 kDa
Theoretical pI9.06
GRAVY-0.374 (hydrophilic)
Aliphatic index87.9
Aromaticity0.079
Instability index38.4 (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
PadRPF03551.21 1.2e-127–80 Transcriptional regulator PadR-like family
Vir_act_alpha_CPF10400.16 5.4e-20105–185 Virulence activator alpha C-term

Experimental structures (Protein Data Bank) 1 solved

PDBMethodResolutionCoverage
8ioi X-ray diffraction 2.94 Å 100%

Experimentally solved structures mapped from the UniProt accession via PDBe/SIFTS (1 total; up to 8 shown, ranked by sequence coverage then resolution). An experimental structure is direct proof of the folded product and the strongest structural evidence — superseding the predicted ESMFold/AlphaFold models below for any covered region.

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 90.6

PDB hitprobTM-scoreE-valueDescription
8ioi-assembly1_A 1.00 0.95 7.2e-26 sig 8ioi-assembly1_A Crystal Structure of PadR- family transcriptional regulator Rv1176c from Mycobacterium tuberculosis H37Rv.
8ioi-assembly1_B 1.00 0.94 7.6e-24 sig 8ioi-assembly1_B Crystal Structure of PadR- family transcriptional regulator Rv1176c from Mycobacterium tuberculosis H37Rv.
5x11-assembly3_C 1.00 0.47 1.5e-09 sig 5x11-assembly3_C Crystal structure of Bacillus subtilis PadR in complex with operator DNA
1yg2-assembly1_A-2 1.00 0.46 2.5e-09 sig 1yg2-assembly1_A-2 Structure of the Vibrio cholerae virulence activator AphA
5x11-assembly3_D 1.00 0.46 2.7e-09 sig 5x11-assembly3_D Crystal structure of Bacillus subtilis PadR in complex with operator DNA

Foldseek search of the AlphaFold DB model (mean pLDDT 90.6, 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)fadH (- strand, -4 bp gap)
Downstream (3' on genome)fdxC (+ strand, 212 bp gap)
Predicted operon fadH · Rv1176c

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) transcription factor

Regulated by (2 TF) Rv0047c (activates) · Rv1176c (activates)
Regulonthis transcription factor regulates 2 target gene(s)

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: fadH (NADPH dependent 2,4-dienoyl-CoA reductase FadH), high confidence from genomic context alone (score 910 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv1175c fadH NADPH dependent 2,4-dienoyl-CoA reductase FadH 910 910 ctx neighborhood:882
Rv3488 hyp hypothetical protein 810 810 coexpression:810
Rv1960c parD1 antitoxin ParD1 740 740 coexpression:740
Rv0158 transcriptional regulator 737 732 coexpression:732
Rv1177 fdxC ferredoxin FdxC 731 732 ctx neighborhood:731
Rv1178 dapC aminotransferase 730 731 ctx neighborhood:727
Rv0744c transcriptional regulator 730 730 coexpression:730
Rv3830c TetR family transcriptional regulator 692 687 coexpression:687
Rv1174c TB8.4 low molecular weight T-cell antigen 517 517 ctx neighborhood:515
Rv1151c cobB NAD-dependent protein deacylase 527 472 coexpression:454
Rv2912c TetR family HTH-type transcriptional regulator 459 449 coexpression:449
Rv3405c HTH-type transcriptional regulator 451 441 coexpression:441
Rv2282c LysR family HTH-type transcriptional regulator 431 431 coexpression:431
Rv1218c tetronasin ABC transporter ATP-binding protein 425 426
Rv3167c TetR family transcriptional regulator 431 420

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: hypothetical protein
  • MTBC0 PGAP product: PadR family transcriptional regulator
  • Pfam (hmmscan --cut_ga): PadR PF03551.21 (E=1e-12), Vir_act_alpha_C PF10400.16 (E=5e-20)
  • (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_215692.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PadR (PF03551.21), Vir_act_alpha_C (PF10400.16)
  • 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 COG1695
  • Curated reference: UniProt O50432 (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 90.6)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 20 functional partner(s); context anchor fadH
  • 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
  • Experimental structures: PDBe/SIFTS UniProt→PDB mapping (Dana et al. 2019, doi:10.1093/nar/gky1114)
  • 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)
  • 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_001265|Rv1176c|
MALPHAILVSLCEQASSGYELARRFDRSIGYFWTATHQQIYRTLRVMENNNWVRATTVLQHGRPDKKVYAISDSGRAELARWIAEPLSPTRPGRGSALTDSSTRDIAVKLRGAGYGDVAALYTQVTALRAERVKSLDTYRGIEKRTFADPSALDGAALHQYLVLRGGIRAEESAIDWLDEVAEALQEKR