vapB43 Family assigned · medium auto-curated

H37Rv Rv2871 · MTBC0 mtbc0_003053 · 85 aa · 3203804–3204061 (+) · RefSeq NP_217387.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)antitoxin VapB43
MTBC0 PGAP re-annotationribbon-helix-helix domain-containing protein
Revised (this work)Ribbon-helix-helix domain-containing protein. Pfam: RHH_1 (PF01402.28).

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

Curated reference (UniProt)

UniProt P9WL41 SwissProt · reviewed · Evidence at protein level
UniProt nameAntitoxin VapB43
Curated functionAntitoxin component of a type II toxin-antitoxin (TA) system. Upon expression in M.smegmatis neutralizes the effect of cognate toxin VapC43.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category K Transcription
Preferred namevapB43
eggNOG descriptionRibbon-helix-helix protein, copG family
Orthologous groupCOG3905
Gene Ontology (12) GO:0005575, GO:0005623, GO:0005886, GO:0008150, GO:0016020, GO:0040008, GO:0044464, GO:0045927, GO:0048518, GO:0050789, GO:0065007, GO:0071944

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 n/a
Polymorphic sites (≥ 0.1% of strains) 0 synonymous, 3 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
RHH_1PF01402.28 6.5e-081–38 Ribbon-helix-helix protein, copG family

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

Closest characterised functional partner: vapC43 (ribonuclease VapC43), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2872 vapC43 ribonuclease VapC43 999 1000 ctx neighborhood:800 experimental:999 textmining:803
Rv2103c vapC37 ribonuclease VapC37 964 965 experimental:960
Rv3697c vapC48 ribonuclease VapC48 869 869 experimental:858
Rv2873 mpt83 cell surface lipoprotein 565 564 ctx neighborhood:562
Rv2870c dxr 1-deoxy-D-xylulose 5-phosphate reductoisomerase 552 551 ctx neighborhood:550
Rv2869c rip zinc metalloprotease 549 549 ctx neighborhood:549
Rv0749 vapC31 ribonuclease VapC31 526 527 experimental:508
Rv0277c vapC25 ribonuclease VapC25 526 527 experimental:508
Rv2868c gcpE 4-hydroxy-3-methylbut-2-en-1-yl diphosphate synthase (flavodoxin) 527 526 ctx neighborhood:526
Rv1242 vapC33 ribonuclease VapC33 525 526 experimental:508
Rv2867c GCN5-like N-acetyltransferase 426 425 ctx neighborhood:425
Rv0617 vapC29 ribonuclease VapC29 406 407
Rv3408 vapC47 ribonuclease VapC47 696 405 textmining:511
Rv1838c vapC13 ribonuclease VapC13 650 405 textmining:437
Rv2494 vapC38 ribonuclease VapC38 404 405

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 VapB43
  • MTBC0 PGAP product: ribbon-helix-helix domain-containing protein
  • Pfam (hmmscan --cut_ga): RHH_1 PF01402.28 (E=6e-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_217387.1)
  • Domains: Pfam-A via hmmscan --cut_ga — RHH_1 (PF01402.28)
  • 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 COG3905
  • Curated reference: UniProt P9WL41 (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 — 40 functional partner(s); context anchor vapC43
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003053|Rv2871|vapB43
MRTTIRIDDELYREVKAKAARSGRTVAAVLEDAVRRGLNPPKPQAAGRYRVQPSGKGGLRPGVDLSSNAALAEAMNDGVSVDAVR