Rv0229c Family assigned · medium
H37Rv Rv0229c · MTBC0 mtbc0_000243 ·
137 aa ·
274687–275100 MTBC0
(-) ·
RefSeq NP_214743.2
Genomic neighbourhood (genome browser)
Open in full genome browser →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) | hypothetical protein |
|---|---|
| MTBC0 PGAP re-annotation | PIN domain nuclease |
| Revised (this work) | PIN-domain ribonuclease, VapC-family toxin (Pfam PIN PF01850): the toxin of a VapBC-type toxin-antitoxin module, a metal-dependent mRNA interferase that cleaves RNA. |
| Functional category (TubercuList) | cell wall and cell processes |
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.
| Publication | Date |
|---|---|
| Mycobacterium tuberculosis Rv0229c Shows Ribonuclease Activity and Reveals Its Corresponding Role as Toxin VapC51. doi:10.3390/antibiotics12050840 | 2023 |
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
| Neighbour | php (Rv0230c, - strand) |
|---|---|
| Overlap | 4 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 -0.20 (95% CI -2.00 to 2.24). 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 |
Mb0234c
· 99.6% identity |
|---|---|
| M. orygis |
RJtmp_000243
· 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 |
L0T5V6
SwissProt · reviewed
· Evidence at protein level
|
|---|---|
| UniProt name | Ribonuclease VapC51 |
| EC (curated) |
EC 3.1.-.-
|
| Curated function | Toxic component of a type II toxin-antitoxin (TA) system. An RNase. Its cognate antitoxin is VapB51. |
Functional vocabulary (eggNOG-mapper, orthology transfer)
| COG category |
S Function unknown
|
|---|---|
| eggNOG description | toxic component of a |
| Orthologous group | COG1487 |
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 | 1.371 · diversifying/relaxed |
|---|---|
| Polymorphic sites (≥ 0.1% of strains) | 1 synonymous, 4 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) 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 19/53 (36%) · mean identity 48.0%
· 3/4 closest MTBAP relatives present in a subset of the genus (19/53 NTM; in 3 of the 4 closest MTBAP relatives) — partial/intermediate conservation |
| Phylostratum (deepest detected homolog) |
MTBC-specific → Mycobacterium → Mycobacteriaceae → Corynebacteriales → Actinomycetia → Bacteria 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) | 17 in the ORF — 0 in the essential state, 0 growth-defect, 17 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 115.058823529. 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 12 of 16 independent MS datasets |
|---|---|
| Integrated abundance | 105.0 ppm · rank 1269/3519 (64.0th 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 | 137 aa |
|---|---|
| Molecular weight | 15.0 kDa |
| Theoretical pI | 6.91 |
| GRAVY | 0.043 (hydrophobic) |
| Aliphatic index | 110.5 |
| Aromaticity | 0.051 |
| Instability index | 37.0 (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 |
|---|---|---|---|---|
PIN | PF01850.28 | 6.6e-11 | 5–120 | PIN domain |
Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 96.3
| PDB hit | prob | TM-score | E-value | Description |
|---|---|---|---|---|
5sv2-assembly1_A-2 |
1.00 | 0.90 | 8.8e-13 sig | 5sv2-assembly1_A-2 Toxin VapC21 from Mycobacterium tuberculosis |
3h87-assembly1_B |
1.00 | 0.88 | 6.5e-11 sig | 3h87-assembly1_B Rv0301 Rv0300 Toxin Antitoxin Complex from Mycobacterium tuberculosis |
6a7v-assembly1_E |
1.00 | 0.82 | 2.9e-09 sig | 6a7v-assembly1_E Crystal structure of Mycobacterium tuberculosis VapBC11 toxin-antitoxin complex |
4chg-assembly3_E |
1.00 | 0.88 | 1.9e-07 sig | 4chg-assembly3_E Crystal structure of VapBC15 complex from Mycobacterium tuberculosis |
5ecw-assembly1_A |
1.00 | 0.82 | 2.2e-07 sig | 5ecw-assembly1_A Structure of the Shigella flexneri VapC mutant D7A |
Foldseek search of the AlphaFold DB model (mean pLDDT 96.3, 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) | Rv0228 (+ strand, 27 bp gap) |
|---|---|
| Downstream (3' on genome) | php (- strand, -4 bp gap) |
| Predicted operon |
Rv0229c · php
|
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 (3 TF) |
Rv0047c (represses) · whiA (activates) · lsr2 (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: php (phosphotriesterase), high confidence from genomic context alone (score 799 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv0230c php |
phosphotriesterase | 902 | 799 ctx | neighborhood:799 textmining:532 |
Rv0231 fadE4 |
acyl-CoA dehydrogenase FadE4 | 562 | 562 ctx | neighborhood:562 |
Rv0582 vapC26 |
ribonuclease VapC26 | 483 | 483 ctx | cooccurence:474 |
Rv0300 vapB2 exp |
antitoxin VapB2 | 444 | 445 | experimental:412 |
Rv1607 chaA |
ionic transporter integral membrane protein ChaA | 440 | 440 ctx | cooccurence:439 |
Rv2601A vapB41 |
antitoxin VapB41 | 434 | 412 | |
Rv1952 vapB14 |
antitoxin VapB14 | 429 | 407 | |
Rv0595c vapC4 |
ribonuclease VapC4 | 440 | 265 | |
Rv0268c hyp |
hypothetical protein | 470 | 69 | textmining:454 |
Rv0366c hyp |
hypothetical protein | 731 | 62 | textmining:726 |
Rv0207c hyp |
hypothetical protein | 803 | 55 | textmining:801 |
Rv3662c hyp |
hypothetical protein | 515 | 52 | textmining:510 |
Rv3641c fic |
cell filamentation protein Fic | 871 | 50 | textmining:870 |
Rv0078A hyp |
hypothetical protein | 804 | 50 | textmining:803 |
Rv2165c rsmH |
rRNA small subunit methyltransferase H | 804 | 47 | textmining:803 |
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: 'PIN domain nuclease'
- Pfam: PIN PF01850 (E=6.6e-11) -- VapC-type metal-dependent RNase
ESM Atlas signal (exploratory)
Ancestral protein hash a578a5f3c4bce26c8788866c3281b74f ·
10 ESM-space neighbours (max similarity 0.924).
SAE features are orienting indices, not validated domains.
| # | Index | Activation | Interpretation |
|---|---|---|---|
| 1 | 12085 |
1.20 | Acidic N-terminal nuclease motif |
| 2 | 304 |
1.06 | PIN/NYN endoribonuclease catalytic core |
| 3 | 6726 |
1.06 | Divalent-metal active-site loops |
| 4 | 15824 |
1.02 | VapC PINc RNase scaffold |
| 5 | 765 |
1.01 | Acidic PIN/NYN endonuclease regions |
| 6 | 5964 |
0.87 | Metallo-phosphoesterase active-site entry |
| 7 | 15408 |
0.86 | Acidic phosphate-binding catalytic helix |
| 8 | 15033 |
0.79 | Acidic metal-binding nuclease active site |
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_214743.2)
- Domains: Pfam-A via hmmscan --cut_ga — PIN (PF01850.28)
- 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
COG1487 - Curated reference: UniProt L0T5V6 (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 96.3)
- 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
php - 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)
- 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_000243|Rv0229c| MALKYLLDTSVIKRLSRPAVRRAVEPLAEAGAVARTQITDLEVGYSARNETEWQRLMVALSAFDLIESTASHHRRALGIQRLLAARSQRGRKIPDLLIAAAGEEHGLVVLHYDADFDLIAAVTGQPCQWIVPAGTID
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