vapB48 Resolved · medium auto-curated

H37Rv Rv3697A · MTBC0 - · 74 aa · 4140239–4140463 (-) · RefSeq YP_007412423.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)antitoxin VapB48
MTBC0 PGAP re-annotation
Revised (this work)Antitoxin VapB48.

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).

Curated reference (UniProt)

UniProt P9WJ15 SwissProt · reviewed · Predicted
UniProt namePutative antitoxin VapB48
Curated functionPossibly the antitoxin component of a type II toxin-antitoxin (TA) system. Its cognate toxin is VapC48.

UniProt still lists this protein as Putative antitoxin VapB48; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

Orthologous group2A15A

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 0.326 · purifying
Polymorphic sites (≥ 0.1% of strains) 3 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)

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

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

Closest characterised functional partner: vapC48 (ribonuclease VapC48), high confidence from genomic context alone (score 882 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3697c vapC48 ribonuclease VapC48 983 882 ctx neighborhood:882 textmining:867
Rv3696c glpK glycerol kinase 651 651 ctx neighborhood:651
Rv3698 hyp hypothetical protein 589 589 ctx neighborhood:589
Rv3699 hyp hypothetical protein 520 520 ctx neighborhood:520
Rv3749c vapC50 hyp hypothetical protein 803 41 textmining:803
Rv0298 antitoxin 800 41 textmining:800
Rv0299 toxin 659 41 textmining:659
Rv3750c vapB50 excisionase 657 41 textmining:657
Rv2019 vapC45 hyp hypothetical protein 655 41 textmining:655
Rv3358 relK toxin RelK 516 41 textmining:516
Rv1246c relE toxin RelE 511 41 textmining:511
Rv1955 higB toxin HigB 439 41 textmining:439
Rv2357c glyS glycine--tRNA ligase 434 41 textmining:434

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

  • Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): antitoxin VapB48
  • (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 YP_007412423.1)
  • 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 2A15A
  • Curated reference: UniProt P9WJ15 (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 — 13 functional partner(s); context anchor vapC48
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv3697A|vapB48
MRTTIDLDDDILRALKRRQREERKTLGQLASELLAQALAAEPPPNVDIRWSTADLRPRVDLDDKDAVWAILDRG