vapB22 Family assigned · medium auto-curated

H37Rv Rv2830c · MTBC0 mtbc0_003009 · 71 aa · 3157675–3157890 (-) · RefSeq NP_217346.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)antitoxin VapB22
MTBC0 PGAP re-annotationtype II toxin-antitoxin system prevent-host-death family antitoxin
Revised (this work)Type II toxin-antitoxin system prevent-host-death family antitoxin. Pfam: PhdYeFM_antitox (PF02604.27).

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

Curated reference (UniProt)

UniProt P71622 SwissProt · reviewed · Evidence at protein level
UniProt nameAntitoxin VapB22
Curated functionAntitoxin component of a type II toxin-antitoxin (TA) system. Upon expression in M.smegmatis neutralizes the effect of cognate toxin VapC22.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category D Cell cycle control, cell division, chromosome partitioning
eggNOG descriptionpositive regulation of growth
Orthologous groupCOG4118
Gene Ontology (34) GO:0006417, GO:0008150, GO:0009889, GO:0009891, GO:0009893, GO:0010468, GO:0010556, GO:0010557, GO:0010604, GO:0010608, GO:0010628, GO:0019222 +22 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 1.366 · 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.

Domains (Pfam, hmmscan --cut_ga)

PfamAccessioni-EvalueResiduesDescription
PhdYeFM_antitoxPF02604.27 4.1e-082–38 Antitoxin Phd_YefM, type II toxin-antitoxin system

Functional interaction network (STRING v12, guilt-by-association)

Closest characterised functional partner: vapC22 (ribonuclease VapC22), high confidence from genomic context alone (score 889 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2829c vapC22 ribonuclease VapC22 921 889 ctx neighborhood:882
Rv2828A hyp hypothetical protein 786 787 ctx neighborhood:787
Rv2828c hyp hypothetical protein 753 753 ctx neighborhood:751
Rv2831 echA16 enoyl-CoA hydratase EchA16 833 648 ctx neighborhood:647 textmining:546
Rv2826c hyp hypothetical protein 401 401
Rv2827c hyp hypothetical protein 401 401
Rv1397c vapC10 ribonuclease VapC10 620 255 textmining:511
Rv2601A vapB41 antitoxin VapB41 478 54 textmining:471
Rv1638A hyp hypothetical protein 529 45 textmining:528
Rv2063A mazF7 mRNA interferase MazF7 434 43 textmining:433
Rv2017 transcriptional regulator 410 42 textmining:410
Rv0959A vapB9 antitoxin VapB9 511 41 textmining:511

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 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: antitoxin VapB22
  • MTBC0 PGAP product: type II toxin-antitoxin system prevent-host-death family antitoxin
  • Pfam (hmmscan --cut_ga): PhdYeFM_antitox PF02604.27 (E=4e-08)
  • (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_217346.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PhdYeFM_antitox (PF02604.27)
  • 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 COG4118
  • Curated reference: UniProt P71622 (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)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 12 functional partner(s); context anchor vapC22
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003009|Rv2830c|vapB22
MTATEVKAKILSLLDEVAQGEEIEITKHGRTVARLVAATGPHALKGRFSGVAMAAVDDDELFTTGVSWNVS