Rv0190 Family assigned · medium

H37Rv Rv0190 · MTBC0 mtbc0_000204 · 96 aa · 222219–222509 MTBC0 (+) · RefSeq NP_214704.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationmetal-sensitive transcriptional regulator
Revised (this work)Metal-sensing transcriptional regulator (Pfam Trns_repr_metal PF02583; CsoR/RcnR-like). Putative metalloregulator controlling metal-homeostasis genes in response to metal ions.
Functional category (TubercuList)conserved hypotheticals

In the literature (TB corpus sweep) 1 publication

Found under: H37Rv (1).

1 TB publication mentions this gene. 1 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
A novel copper-responsive regulon in Mycobacterium tuberculosis. doi:10.1111/j.1365-2958.2010.07431.x 2011

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.

Phenotype-driven functional lead (hypothesis) priority 5.0

disruption sensitises to Isoniazid (cell-envelope / intrinsic drug tolerance); disruption advantageous under acid stress in phosphate-citrate buffer.

Corroborating evidenceconserved / under constraint intra-MTBC; STRING-coupled to ilvD (dihydroxy-acid dehydratase); structural lead available

This locus is a "hypothetical" with a conditional Tn-seq phenotype. The statement above is a working hypothesis for its functional context, synthesised from the phenotype pattern and the corroborating layers on this page (conservation, STRING coupling, operon, regulon, localisation, structure) — a prioritised requalification candidate to validate, not an established function.

Conditional expression context (iModulons)

Member of 1 independently-modulated gene set(s): RicR (ricR).

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).

Post-translational modifications

1 reported modified residue(s): N-acetylthreonine @2.

Experimentally reported post-translational modification(s). A phosphosite indicates the protein is expressed and is a substrate of the M. tuberculosis Ser/Thr/Tyr kinase signalling network — a regulatory context, NOT a molecular function. Source: UniProt (Modified residue features; PTM sites curated from the M. tuberculosis literature).

CRISPRi vulnerability

Vulnerability index -0.82 (95% CI -2.96 to 1.68). 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)). 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 Mb0196 · 100.0% identity
M. leprae ML2609 · 82.6% identity
M. marinum MMAR_0433 · 90.6% identity
M. smegmatis MSMEG_0230 · 80.0% identity
M. orygis RJtmp_000205 · 100.0% identity
M. abscessus MAB_4542c · 78.9% 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 O07434 SwissProt · reviewed · Evidence at protein level
UniProt nameCopper-sensing transcriptional repressor RicR
Curated functionUnder low copper conditions, represses the expression of lpqS, Rv2963, mymT, socA, socB, mmcO and its own expression. In the presence of copper, RicR dissociates from DNA, leading to the expression of the target genes. Members of the RicR regulon are important for copper resistance during infections and full virulence in a mouse model of infection.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
Preferred namecsoR
eggNOG descriptionMetal-sensitive transcriptional repressor
Orthologous groupCOG1937
KEGG orthology K21600
Gene Ontology (59) GO:0000976, GO:0001067, GO:0001130, GO:0001217, GO:0003674, GO:0003676, GO:0003677, GO:0003690, GO:0003700, GO:0005488, GO:0005575, GO:0006355 +47 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)

pN/pS 0.0 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 0 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

Genus-wide presence (~53 non-MTBC Mycobacterium) present in 53/53 (100%) · mean identity 87.7% · 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 11/13 non-Mycobacterium reference genomes (down to Bacteria) · mean identity 61.8%
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 callGA · growth-advantage
What the call meansgrowth-advantage: insertions enriched
TA sites (Himar1) 3 in the ORF — 0 in the essential state, 0 growth-defect, 0 non-essential, 3 growth-advantage. Saturation 1.000, mean read count 166.333333333. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction.
CaveatStatistically thin call: only 3 TA (Himar1) sites in the whole ORF (atlas median 13; genes under 300 nt typically have very few). A DeJesus 2017 call built on so few independent observations is less robust than the same call on a longer gene, in either direction. Cross-check against the CRISPRi vulnerability index (independent of TA-site density) and, if this gene overlaps a neighbour (see Genomic-neighbour overlap section below), verify how many of its TA sites actually fall inside its own ORF. (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)

Conditionlog2FCqEffect
altered fitness under Isoniazid (drug exposure) -2.230.02 required
altered fitness under acid stress in phosphate-citrate buffer (stress) +2.160.0078 disruption advantageous

Conditional fitness of transposon-disruption mutants across 2 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 12 of 16 independent MS datasets
Integrated abundance273.0 ppm · rank 690/3519 (80.4th 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)

Length96 aa
Molecular weight10.4 kDa
Theoretical pI8.71
GRAVY-0.164 (hydrophilic)
Aliphatic index96.7
Aromaticity0.031
Instability index32.2 (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
Trns_repr_metalPF02583.23 3.4e-3011–91 Metal-sensitive transcriptional repressor

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 91.7

PDB hitprobTM-scoreE-valueDescription
4uig-assembly1_A 1.00 0.93 2.4e-07 sig 4uig-assembly1_A Structure of the copper sensitive operon repressor from Streptomyces lividans at pH6
4adz-assembly1_A-2 1.00 0.93 9.4e-07 sig 4adz-assembly1_A-2 Crystal Structure of the apo form of a Copper-sensitive operon Regulator (CsoR) protein from Streptomyces lividans
4m1p-assembly1_A 1.00 0.91 3.4e-05 sig 4m1p-assembly1_A Crystal structure of the copper-sensing repressor CsoR with Cu(I) from Geobacillus thermodenitrificans NG80-2
5fmn-assembly1_B 1.00 0.80 2.6e-04 sig 5fmn-assembly1_B The nickel-responsive transcriptional regulator InrS
7mq3-assembly1_A 1.00 0.70 1.9e-03 sig 7mq3-assembly1_A C9A N55A Streptococcus pneumoniae CstR in the reduced state

Foldseek search of the AlphaFold DB model (mean pLDDT 91.7, 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)ilvD (- strand, 147 bp gap)
Downstream (3' on genome)Rv0191 (+ strand, 127 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: ilvD (dihydroxy-acid dehydratase), high confidence from genomic context alone (score 773 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv0189c ilvD dihydroxy-acid dehydratase 773 773 ctx neighborhood:772
Rv0191 MFS-type transporter 859 763 ctx neighborhood:759 textmining:434
Rv2259 mscR S-nitrosomycothiol reductase MscR 484 464 coexpression:433
Rv3086 adhD alcohol dehydrogenase D 480 460 coexpression:429
Rv0761c adhB alcohol dehydrogenase B 480 460 coexpression:429
Rv0162c adhE1 zinc-type alcohol dehydrogenase subunit E 480 460 coexpression:429
Rv0192 hyp hypothetical protein 452 452 ctx neighborhood:449
Rv0129c fbpC diacylglycerol acyltransferase/mycolyltransferase Ag85C 449 429 coexpression:411
Rv3804c fbpA diacylglycerol acyltransferase/mycolyltransferase Ag85A 448 427 coexpression:409
Rv1288 hyp hypothetical protein 453 426 coexpression:407
Rv0774c hyp hypothetical protein 446 425 coexpression:407
Rv1639c hyp hypothetical protein 446 425 coexpression:407
Rv3803c fbpD MPT51/MPB51 antigen 446 425 coexpression:407
Rv1886c fbpB diacylglycerol acyltransferase/mycolyltransferase Ag85B 446 425 coexpression:407
Rv3286c sigF exp RNA polymerase sigma factor SigF 406 406 experimental:406

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

  • MTBC0 PGAP product: 'metal-sensitive transcriptional regulator'
  • Pfam: Trns_repr_metal PF02583 (E=3.4e-30)

ESM Atlas signal (exploratory)

Ancestral protein hash b2780861c6f503efd9cea59685ca7b08 · 10 ESM-space neighbours (max similarity 0.933). SAE features are orienting indices, not validated domains.

#IndexActivationInterpretation
19309 0.77 Solvent-exposed interaction patches
213240 0.60 Amphipathic core helices
31304 0.53 N-terminal first-folded block
410679 0.48 Charged N-terminal subdomain activation
512874 0.45 C-terminal assembly region
63509 0.37 Terminal helix-to-IDR tails
713156 0.36 Basic polar N-terminal leaders
812554 0.35 Charged disordered interface loops

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_214704.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Trns_repr_metal (PF02583.23)
  • 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 COG1937
  • Curated reference: UniProt O07434 (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 91.7)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 31 functional partner(s); context anchor ilvD
  • 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)
  • 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_000204|Rv0190|
MTAAHGYTQQKDNYAKRLRRVEGQVRGIARMIEEDKYCIDVLTQISAVTSALRSVALNLLDEHLSHCVTRAVAEGGPGADGKLAEASAAIARLVRS