vapB5 Family assigned · medium auto-curated

H37Rv Rv0626 · MTBC0 mtbc0_000659 · 86 aa · 721578–721838 (+) · RefSeq NP_215140.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)antitoxin VapB5
MTBC0 PGAP re-annotationtype II toxin-antitoxin system Phd/YefM family antitoxin
Revised (this work)Type II toxin-antitoxin system Phd/YefM 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 P9WF19 SwissProt · reviewed · Evidence at protein level
UniProt namePutative antitoxin VapB5
Curated functionProbable antitoxin component of a type II toxin-antitoxin (TA) system. The cognate toxin is VapC5.

UniProt still lists this protein as Putative antitoxin VapB5; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category D Cell cycle control, cell division, chromosome partitioning
eggNOG descriptionAntitoxin component of a toxin-antitoxin (TA) module
Orthologous groupCOG4118
Gene Ontology (9) GO:0003674, GO:0005488, GO:0008150, GO:0015643, GO:0040008, GO:0045927, GO:0048518, GO:0050789, GO:0065007

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 0.199 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 1 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 1.2e-071–42 Antitoxin Phd_YefM, type II toxin-antitoxin system

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

Closest characterised functional partner: vapC5 (ribonuclease VapC5), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0627 vapC5 ribonuclease VapC5 999 1000 ctx neighborhood:882 cooccurence:769 experimental:999 textmining:818
Rv0665 vapC8 ribonuclease VapC8 978 977 ctx cooccurence:772 experimental:891
Rv0595c vapC4 ribonuclease VapC4 977 977 ctx cooccurence:771 experimental:891
Rv3408 vapC47 ribonuclease VapC47 710 710 ctx cooccurence:702
Rv3384c vapC46 ribonuclease VapC46 636 636 ctx cooccurence:620
Rv3479 transmembrane protein 604 604 ctx cooccurence:604
Rv0625c transmembrane protein 582 582 ctx neighborhood:579
Rv1962c vapC35 ribonuclease VapC35 547 548 ctx cooccurence:539
Rv3385c vapB46 antitoxin VapB46 545 545 ctx cooccurence:537
Rv3697c vapC48 ribonuclease VapC48 541 541 ctx cooccurence:530
Rv1953 vapC14 ribonuclease VapC14 529 529 experimental:513
Rv2103c vapC37 ribonuclease VapC37 524 525 ctx cooccurence:511
Rv0749 vapC31 ribonuclease VapC31 520 521 ctx cooccurence:509
Rv1242 vapC33 ribonuclease VapC33 488 489 ctx cooccurence:478
Rv2872 vapC43 ribonuclease VapC43 476 476 ctx cooccurence:465

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 VapB5
  • MTBC0 PGAP product: type II toxin-antitoxin system Phd/YefM family antitoxin
  • Pfam (hmmscan --cut_ga): PhdYeFM_antitox PF02604.27 (E=1e-07)
  • (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_215140.1)
  • 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 P9WF19 (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 — 29 functional partner(s); context anchor vapC5
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000659|Rv0626|vapB5
MSEVASRELRNDTAGVLRRVRAGEDVTITVSGRPVAVLTPVRPRRRRWLSKTEFLSRLRGAQADPGLRNDLAVLAGDTTEDLGPIR