Rv0143c Resolved · high auto-curated
H37Rv Rv0143c · MTBC0 mtbc0_000154 ·
492 aa ·
169050–170528 MTBC0
(-) ·
RefSeq NP_214657.1
Genomic neighbourhood (genome browser)
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Annotation: from legacy to revised
| Legacy (H37Rv / Mycobrowser) | transmembrane protein |
|---|---|
| MTBC0 PGAP re-annotation | chloride channel protein |
| Revised (this work) | Chloride channel protein. Pfam: Voltage_CLC (PF00654.26). |
| Functional category (TubercuList) | cell wall and cell processes |
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 1.22 (95% CI -0.65 to 4.32). 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 function | Unknown; possibly ion channel involved in transport of chloride across the membrane. |
|---|
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 Mycobrowser is no longer maintained; its EC numbers predate recent nomenclature revisions, so a class change usually reflects re-numbering, not a conflict.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 |
Mb0148c
· 99.8% identity |
|---|---|
| M. marinum |
MMAR_0353
· 87.9% identity |
| M. smegmatis |
MSMEG_6465
· 67.3% identity |
| M. orygis |
RJtmp_000154
· 99.8% 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 |
P96820
TrEMBL · unreviewed
· Evidence at protein level
|
|---|---|
| UniProt name | Probable conserved transmembrane protein |
Functional vocabulary (eggNOG-mapper, orthology transfer)
| COG category |
P Inorganic ion transport and metabolism
|
|---|---|
| Preferred name | clcA |
| eggNOG description | Chloride channel |
| Orthologous group | COG0038 |
| KEGG orthology |
K03281
|
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 | 0.487 · purifying |
|---|---|
| Polymorphic sites (≥ 0.1% of strains) | 7 synonymous, 8 missense, 1 nonsense, 2 frameshift |
| Disruption | 3 distinct premature-stop/frameshift site(s); most common in 0.73% of strains (1056) · 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) |
0.0 (low power)
· 2 consensus substitution(s) low power (2 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable |
|---|---|
| Genus-wide presence (~53 non-MTBC Mycobacterium) |
present in 34/53 (64%) · mean identity 83.4%
· 4/4 closest MTBAP relatives conserved across the genus (present in 34/53 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 3/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 48.0% 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 call | NE · non-essential |
|---|---|
| What the call means | non-essential |
| TA sites (Himar1) | 28 in the ORF — 0 in the essential state, 0 growth-defect, 28 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 136.5. 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 detection | detected in 10 of 16 independent MS datasets |
|---|---|
| Integrated abundance | 10.1 ppm · rank 2679/3519 (23.9th 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)
| Prediction | predicted membrane protein (10 TM helixes) |
|---|---|
| DeepTMHMM class | TM |
| TM helices (DeepTMHMM) | 10 |
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)
| Length | 492 aa |
|---|---|
| Molecular weight | 50.8 kDa |
| Theoretical pI | 7.79 |
| GRAVY | 0.574 (hydrophobic) |
| Aliphatic index | 110.9 |
| Aromaticity | 0.089 |
| Instability index | 23.1 (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)
| Pfam | Accession | i-Evalue | Residues | Description |
|---|---|---|---|---|
Voltage_CLC | PF00654.26 | 3.0e-85 | 113–460 | Voltage gated chloride channel |
Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 91.4
| PDB hit | prob | TM-score | E-value | Description |
|---|---|---|---|---|
7n9w-assembly1_B |
1.00 | 0.81 | 9.4e-17 sig | 7n9w-assembly1_B CLC-ec1 pH 4.5 100mM Cl Twist1 |
8gah-assembly1_A |
1.00 | 0.81 | 2.9e-16 sig | 8gah-assembly1_A CLC-ec1 L25C/A450C/C85A at pH 4.5 100mM Cl Twist |
2htk-assembly1_B |
1.00 | 0.82 | 1.1e-15 sig | 2htk-assembly1_B Structure of the Escherichia coli ClC chloride channel Y445A mutant and Fab complex |
7rsb-assembly1_B |
1.00 | 0.81 | 6.6e-16 sig | 7rsb-assembly1_B CLC-ec1 at pH 4.5 100 mM NaGluconate Turn |
6v2j-assembly1_A-2 |
1.00 | 0.82 | 1.3e-15 sig | 6v2j-assembly1_A-2 Crystal structure of ClC-ec1 triple mutant (E113Q, E148Q, E203Q) |
Foldseek search of the AlphaFold DB model (mean pLDDT 91.4, 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)
| Upstream (5' on genome) | Rv0142 (+ strand, 66 bp gap) |
|---|---|
| Downstream (3' on genome) | Rv0144 (+ strand, 101 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: Rv0144 (transcriptional regulator), medium confidence from genomic context alone (score 559 excluding text-mining).
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv0144 |
transcriptional regulator | 560 | 559 ctx | neighborhood:555 |
Rv1762c hyp |
hypothetical protein | 452 | 452 ctx | cooccurence:421 |
Rv2101 helZ |
helicase HelZ | 470 | 438 | |
Rv3432c gadB |
glutamate decarboxylase GadB | 466 | 432 | |
Rv0145 |
S-adenosylmethionine-dependent methyltransferase | 417 | 418 ctx | neighborhood:414 |
Rv0146 |
S-adenosylmethionine-dependent methyltransferase | 415 | 415 ctx | neighborhood:413 |
Rv3256c hyp |
hypothetical protein | 436 | 409 | coexpression:409 |
Rv1899c lppD |
lipoprotein LppD | 403 | 403 | |
Rv3907c pcnA |
poly(A) polymerase PcnA | 414 | 47 | textmining:411 |
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: transmembrane protein
- MTBC0 PGAP product: chloride channel protein
- Pfam (hmmscan --cut_ga): Voltage_CLC PF00654.26 (E=3e-85)
- (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_214657.1)
- Domains: Pfam-A via hmmscan --cut_ga — Voltage_CLC (PF00654.26)
- 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
COG0038 - Curated reference: UniProt P96820 (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 91.4)
- Interaction network: STRING v12.0 (Szklarczyk et al. 2023,
doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 —
9 functional partner(s); context anchor
Rv0144 - 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
- Primary literature: none located yet; annotation rests on the domain/homology sources above.
Ancestral MTBC0 protein sequence
>mtbc0_000154|Rv0143c| MAPGDWSVFAWHAANLPTMPEAEDIGNEAAGGRFGVSIRSAGYLRKWFLLGITIGVIAGLGAVVFYLALKYTSEFLLGYLADYQIPTPVGEGGHRGSTGFARPWAIPLVTTGGAVLSALIVAKLAPEATGHGTDEAIESVHGDPRAIRGRAVLVKMVASALTIGSGGSGGREGPTAQISAGFCSLLTRRLNLSNEDGRTAVALGIGAGIGAIFAAPLGGAALGASIPYRDDFDYRNLLPGFIASGTAYAVLGAFLGFDPLFGYIDAEYRFEKAWPLLWFVVIGLIAAAVGYLYARVFHASVAITRRLPGGPVLKPAIGGLLVGLLGLPIPQILSSGYGWAQLAADRGTLLSIPLWIVIVLPIAKILATSLSIGTGGSGGLFGPGIVIGAFVGAAIWRLGELTELPGVPHEPGIFVVVAMMACFGSVSRAPLAVMIMVAEMTGSFSVVPGAIIAVGIAALLLSRTNVTIYETQRLNRQTAEAERGGSDRPTTA
Spot an error? Suggest an improvement
Found a mistake, a missing reference, or have a better functional hypothesis for Rv0143c? Email the maintainer — the message is pre-filled with this gene's details.