vapB7 Resolved · medium auto-curated

H37Rv Rv0662c · MTBC0 mtbc0_000700 · 84 aa · 759855–760109 (-) · RefSeq NP_215176.2

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)antitoxin VapB7
MTBC0 PGAP re-annotationantitoxin
Revised (this work)Antitoxin.

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

Curated reference (UniProt)

UniProt O06777 SwissProt · reviewed · Predicted
UniProt namePutative antitoxin VapB7
Curated functionAntitoxin component of a possible type II toxin-antitoxin (TA) system. The cognate toxin is VapC7.

UniProt still lists this protein as Putative antitoxin VapB7; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

Orthologous group2ERR5
Gene Ontology (6) GO:0005575, GO:0005623, GO:0005886, GO:0016020, GO:0044464, 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, 2 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)

No Pfam-A domain above the gathering threshold (or not yet scanned).

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

Closest characterised functional partner: vapC7 (ribonuclease VapC7), high confidence from genomic context alone (score 886 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0661c vapC7 ribonuclease VapC7 942 886 ctx neighborhood:882 textmining:511
Rv0660c mazE2 antitoxin MazE2 562 562 ctx neighborhood:560
Rv0663 atsD arylsulfatase AtsD 541 541 ctx neighborhood:540
Rv0659c mazF2 toxin MazF2 525 525 ctx neighborhood:524
Rv0664 vapB8 antitoxin VapB8 475 476 ctx neighborhood:473
Rv0665 vapC8 ribonuclease VapC8 475 475 ctx neighborhood:473
Rv0666 membrane protein 474 475 ctx neighborhood:473
Rv3833 AraC family transcriptional regulator 462 55 textmining:455
Rv2640c ArsR family transcriptional regulator 416 52 textmining:410
Rv2865 relF antitoxin RelF 440 51 textmining:435
Rv2872 vapC43 ribonuclease VapC43 809 50 textmining:808
Rv1960c parD1 antitoxin ParD1 519 50 textmining:515
Rv3167c TetR family transcriptional regulator 518 50 textmining:514
Rv1721c vapB12 antitoxin VapB12 522 47 textmining:519
Rv2871 vapB43 antitoxin VapB43 807 46 textmining:806

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 VapB7
  • MTBC0 PGAP product: antitoxin
  • (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_215176.2)
  • Domains: Pfam-A via hmmscan --cut_ga — none above threshold
  • 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 2ERR5
  • Curated reference: UniProt O06777 (SwissProt, reviewed; Predicted)
  • 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 — 19 functional partner(s); context anchor vapC7
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000700|Rv0662c|vapB7
MSMRLAHRLQILLDDECHRRITAVARERGVPVATVVREAIDRGLVSPAGRRKSAGRRLLDAADMSVPEPRELKQELEALRARRG