vapB11 Resolved · high auto-curated
H37Rv Rv1560 · MTBC0 - ·
72 aa ·
1764755–1764973 H37Rv
(+) ·
RefSeq NP_216076.1
Genomic neighbourhood (genome browser)
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Annotation: from legacy to revised
| Legacy (H37Rv / Mycobrowser) | antitoxin VapB11 |
|---|---|
| MTBC0 PGAP re-annotation | — |
| Revised (this work) | Antitoxin VapB11. Pfam: VapB_antitoxin (PF09957.16). |
| 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) 2 publications
2 TB publications mention this gene. 2 publication(s) discuss this gene (2 in a M. tuberculosis context).
| Publication | Date |
|---|---|
| Toxin-antitoxin system gene mutations driving Mycobacterium tuberculosis transmission revealed by whole genome sequencing. doi:10.3389/fmicb.2024.1398886 | 2024 |
| Toxin-antitoxin systems shows variability among Mycobacterium tuberculosis lineages. doi:10.1093/femsle/fny276 | 2019 |
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 disorder | 36% of residues (metapredict) · mean AlphaFold pLDDT 85.1 |
|---|---|
| Disordered regions | 1 IDR(s), longest 18 aa [54-72] |
carries a substantial disordered region (18/72 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).
CRISPRi vulnerability
Vulnerability index 0.11 (95% CI -2.62 to 3.35). 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).
Orthologues (reciprocal best hits across mycobacteria)
| M. bovis |
Mb1586
· 98.6% identity |
|---|---|
| M. orygis |
RJtmp_001648
· 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 |
P9WLU3
SwissProt · reviewed
· Evidence at protein level
|
|---|---|
| UniProt name | Antitoxin VapB11 |
| Curated function | Antitoxin component of a type II toxin-antitoxin (TA) system. Upon expression in E.coli and M.smegmatis neutralizes the effect of cognate toxin VapC11. |
Functional vocabulary (eggNOG-mapper, orthology transfer)
| COG category |
K Transcription
|
|---|---|
| eggNOG description | Bacterial antitoxin of type II TA system, VapB |
| Orthologous group | COG5450 |
| Gene Ontology (45) |
GO:0006417, GO:0008150, GO:0009605, GO:0009607, GO:0009889, GO:0009891, GO:0009893, GO:0010468, GO:0010556, GO:0010557, GO:0010604, GO:0010608 +33 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
| M. canettii dN/dS (deep-divergence selection) |
0.0 (low power)
· 1 consensus substitution(s) low power (1 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable |
|---|---|
| Genus-wide presence (~53 non-MTBC Mycobacterium) |
present in 15/53 (28%) · mean identity 52.4%
· 3/4 closest MTBAP relatives present in a subset of the genus (15/53 NTM; in 3 of the 4 closest MTBAP relatives) — partial/intermediate conservation |
| Phylostratum (deepest detected homolog) |
MTBC-specific → Mycobacterium → Mycobacteriaceae → Corynebacteriales → Actinomycetia → Bacteria short ORF (72 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 call | NE · non-essential |
|---|---|
| What the call means | non-essential |
| TA sites (Himar1) | 3 in the ORF — 0 in the essential state, 0 growth-defect, 3 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 18. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction. |
| Caveat | Statistically 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.
Proteomics (mass spectrometry) detected
| MS detection | detected in 7 of 16 independent MS datasets |
|---|---|
| Integrated abundance | 26.3 ppm · rank 2146/3519 (39.0th 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)
| Length | 72 aa |
|---|---|
| Molecular weight | 8.2 kDa |
| Theoretical pI | 4.85 |
| GRAVY | -0.347 (hydrophilic) |
| Aliphatic index | 93.5 |
| Aromaticity | 0.069 |
| Instability index | 73.5 (unstable) |
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 |
|---|---|---|---|---|
VapB_antitoxin | PF09957.16 | 1.6e-18 | 7–49 | Bacterial antitoxin of type II TA system, VapB |
Experimental structures (Protein Data Bank) 1 solved
| PDB | Method | Resolution | Coverage |
|---|---|---|---|
6a7v |
X-ray diffraction | 1.67 Å | 86% |
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 85.1
| PDB hit | prob | TM-score | E-value | Description |
|---|---|---|---|---|
6a7v-assembly1_U |
1.00 | 0.60 | 3.1e-08 sig | 6a7v-assembly1_U Crystal structure of Mycobacterium tuberculosis VapBC11 toxin-antitoxin complex |
6a7v-assembly1_H |
1.00 | 0.68 | 1.8e-07 sig | 6a7v-assembly1_H Crystal structure of Mycobacterium tuberculosis VapBC11 toxin-antitoxin complex |
Foldseek search of the AlphaFold DB model (mean pLDDT 85.1, 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 5
| Upstream (5' on genome) | ilvA (+ strand, 37 bp gap) |
|---|---|
| Downstream (3' on genome) | vapC11 (+ strand, 5 bp gap) |
| Predicted operon |
mmpL6 · Rv1558 · ilvA · vapB11 · vapC11
|
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 (2 TF) |
Rv0135c (represses) · Rv1353c (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: vapC11 (ribonuclease VapC11), high confidence from genomic context alone (score 1000 excluding text-mining).
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv1561 vapC11 exp |
ribonuclease VapC11 | 999 | 1000 ctx | neighborhood:882 cooccurence:703 coexpression:817 experimental:999 |
Rv2010 vapC15 exp |
ribonuclease VapC15 | 961 | 961 ctx | cooccurence:706 experimental:853 |
Rv1151c cobB |
NAD-dependent protein deacylase | 765 | 765 | coexpression:765 |
Rv1395 |
HTH-type transcriptional regulator | 733 | 733 | coexpression:733 |
Rv1960c parD1 |
antitoxin ParD1 | 733 | 733 | coexpression:732 |
Rv3263 |
DNA methylase | 732 | 732 | coexpression:732 |
Rv0273c |
transcriptional regulator | 731 | 731 | coexpression:731 |
Rv0624 vapC30 |
ribonuclease VapC30 | 685 | 686 ctx | cooccurence:509 |
Rv1559 ilvA |
threonine dehydratase IlvA | 667 | 667 ctx | neighborhood:659 |
Rv0158 |
transcriptional regulator | 651 | 651 | coexpression:651 |
Rv2759c vapC42 |
ribonuclease VapC42 | 623 | 624 ctx | cooccurence:529 |
Rv3488 hyp |
hypothetical protein | 615 | 615 | coexpression:615 |
Rv0603 hyp |
hypothetical protein | 580 | 580 | coexpression:580 |
Rv1558 hyp |
hypothetical protein | 566 | 565 ctx | neighborhood:563 |
Rv1557 mmpL6 |
transmembrane transport protein MmpL6 | 561 | 561 ctx | neighborhood:556 |
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): antitoxin VapB11
- Pfam (hmmscan --cut_ga): VapB_antitoxin PF09957.16 (E=2e-18)
- (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_216076.1)
- Domains: Pfam-A via hmmscan --cut_ga — VapB_antitoxin (PF09957.16)
- 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
COG5450 - Curated reference: UniProt P9WLU3 (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 85.1)
- Interaction network: STRING v12.0 (Szklarczyk et al. 2023,
doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 —
29 functional partner(s); context anchor
vapC11 - 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
>H37Rv|Rv1560|vapB11 MYRWCMSRTNIDIDDELAAEVMRRFGLTTKRAAVDLALRRLVGSPLSREFLLGLEGVGWEGDLDDLRSDRPD
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