mymT Resolved · medium auto-curated

H37Rv Rv0186A · MTBC0 - · 53 aa · 218390–218551 H37Rv (-) · RefSeq YP_004837046.2

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)metallothionein
MTBC0 PGAP re-annotation
Revised (this work)Metallothionein.
Functional category (TubercuList)virulence, detoxification, adaptation

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

Annotated on the H37Rv protein: this gene has no 1:1 ancestral MTBC0 anchor (PE/PPE, paralogue, IS element, or otherwise unanchored CDS).

In the literature (TB corpus sweep) 4 publications

4 TB publications mention this gene. 4 publication(s) discuss this gene (3 in a M. tuberculosis context).

PublicationDate
Resistance mechanisms of Mycobacterium tuberculosis against phagosomal copper overload. doi:10.1016/j.tube.2011.12.006 2012
Bacterial metallothioneins: past, present, and questions for the future. doi:10.1007/s00775-011-0790-y 2011
A novel copper-responsive regulon in Mycobacterium tuberculosis. doi:10.1111/j.1365-2958.2010.07431.x 2011
Identification of a copper-binding metallothionein in pathogenic mycobacteria. doi:10.1038/nchembio.109 2008

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.

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).

CRISPRi vulnerability

Vulnerability index 0.13 (95% CI -0.79 to 1.35). 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 functionCoordinates Cu(I) ions into a Cu(I)-thiolate core, protects cell from copper toxicity

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 Mb0192A · 100.0% identity
M. marinum MMAR_5584 · 74.0% identity
M. orygis RJtmp_000201 · 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 P9WK09 SwissProt · reviewed · Evidence at protein level
UniProt nameMetallothionein
Curated functionMetallothioneins are small proteins that have a high content of cysteine residues which allow them to bind heavy metal ions through clusters of thiolate bonds. MymT binds up to seven ions of Cu(+), with a preference for four to six Cu(+) ions, in a solvent-shielded core. MymT protects M.tuberculosis from copper toxicity.

Functional vocabulary (eggNOG-mapper, orthology transfer)

Orthologous group2B11Q
KEGG orthology K21609
Gene Ontology (28) GO:0003674, GO:0005488, GO:0005507, GO:0008150, GO:0008270, GO:0010035, GO:0010038, GO:0010043, GO:0010045, GO:0032025, GO:0042221, GO:0042592 +16 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.

Outgroup conservation (beyond the MTBC) Mycobacterium

Genus-wide presence (~53 non-MTBC Mycobacterium) present in 50/53 (94%) · mean identity 75.1% · 4/4 closest MTBAP relatives
conserved across the genus (present in 50/53 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

short ORF (53 aa) a shallow stratum may reflect homology-detection failure, not true youth
present across the genus Mycobacterium (NTM) but not detected in any non-Mycobacterium genome — a Mycobacterium-genus 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) 4 in the ORF — 0 in the essential state, 0 growth-defect, 4 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 157. 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 4 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.

Proteomics (mass spectrometry) detected

MS detectiondetected in 10 of 16 independent MS datasets
Integrated abundance510.0 ppm · rank 396/3519 (88.8th 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 17

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)

Length53 aa
Molecular weight5.7 kDa
Theoretical pI6.68
GRAVY-0.03 (hydrophilic)
Aliphatic index68.1
Aromaticity0.038
Instability index26.7 (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)

No Pfam-A domain above the gathering threshold (or not yet scanned).

Genomic context (neighbours & predicted operon)

Upstream (5' on genome)bglS (+ strand, 45 bp gap)
Downstream (3' on genome)Rv0187 (+ strand, 153 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: Rv0187 (O-methyltransferase), medium confidence from genomic context alone (score 649 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0187 O-methyltransferase 648 649 ctx neighborhood:649
Rv0188 transmembrane protein 535 358
Rv0190 ricR hyp hypothetical protein 870 41 textmining:870
Rv0847 lpqS lipoprotein LpqS 870 41 textmining:870
Rv2963 integral membrane protein 870 41 textmining:870
Rv0846c mmcO oxidase 870 41 textmining:870
Rv0967 csoR copper-sensing transcriptional repressor CsoR 804 41 textmining:804
Rv0969 ctpV copper-exporting ATPase 655 41 textmining:655
Rv2683 hyp hypothetical protein 583 41 textmining:583
Rv0850 Rv0850, (MTV043.43), len: 110 aa. Putative transposase (fragment), similar in part to others e.g. Q45144|Q4514 transposable element IS31831 582 41 textmining:582
Rv0848 cysK2 cysteine synthase CysK 546 41 textmining:546
Rv0849 MFS-type transporter 532 41 textmining:532
Rv2641 cadI cadmium inducible protein CadI 511 41 textmining:511
Rv0970 integral membrane protein 510 41 textmining:510
Rv1946c lppG lipoprotein 510 41 textmining:510

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

  • Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): metallothionein
  • (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 YP_004837046.2)
  • Domains: Pfam-A via hmmscan --cut_ga — none above threshold
  • 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 2B11Q
  • Curated reference: UniProt P9WK09 (SwissProt, reviewed; Evidence at protein level)
  • 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 85.3)
  • 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 Rv0187
  • 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

>H37Rv|Rv0186A|mymT
MRVIRMTNYEAGTLLTCSHEGCGCRVRIEVPCHCAGAGDAYRCTCGDELAPVK