Rv3181c Family assigned · medium auto-curated

H37Rv Rv3181c · MTBC0 mtbc0_003382 · 150 aa · 3574539–3574991 (-) · RefSeq NP_217697.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)antitoxin VapB45
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 P9WF15 SwissProt · reviewed · Evidence at protein level
UniProt namePutative antitoxin VapB49
Curated functionPossibly the antitoxin component of a type II toxin-antitoxin (TA) system. Its cognate toxin is VapC49 (Potential).

UniProt still lists this protein as Putative antitoxin VapB49; 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 (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, 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 4.1e-1067–116 Antitoxin Phd_YefM, type II toxin-antitoxin system

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

Closest characterised functional partner: vapC49 (ribonuclease VapC45), high confidence from genomic context alone (score 972 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3180c vapC49 ribonuclease VapC45 995 972 ctx neighborhood:882 cooccurence:773 textmining:857
Rv2308 hyp hypothetical protein 651 652 ctx cooccurence:637
Rv0355c PPE8 PPE family protein PPE8 646 646 ctx cooccurence:646
Rv2490c PE_PGRS43 PE-PGRS family protein PE_PGRS43 637 637 ctx cooccurence:637
Rv1452c PE_PGRS28 PE-PGRS family protein PE_PGRS28 634 634 ctx cooccurence:634
Rv3347c PPE55 PPE family protein PPE55 632 632 ctx cooccurence:632
Rv3350c PPE56 PPE family protein PPE56 628 628 ctx cooccurence:628
Rv0613c hyp hypothetical protein 627 627 ctx cooccurence:627
Rv1917c PPE34 PPE family protein PPE34 625 625 ctx cooccurence:623
Rv2209 integral membrane protein 622 622 ctx cooccurence:621
Rv0665 vapC8 ribonuclease VapC8 606 606 ctx cooccurence:495
Rv0872c PE_PGRS15 PE-PGRS family protein PE_PGRS15 604 604 ctx cooccurence:604
Rv0304c PPE5 PPE family protein PPE5 603 603 ctx cooccurence:603
Rv0341 iniB isoniazid inducible protein IniB 603 603 ctx cooccurence:601
Rv1004c membrane protein 603 603 ctx cooccurence:601

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 VapB45
  • MTBC0 PGAP product: type II toxin-antitoxin system Phd/YefM family antitoxin
  • Pfam (hmmscan --cut_ga): PhdYeFM_antitox PF02604.27 (E=4e-10)
  • (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_217697.1)
  • 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 P9WF15 (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 — 86 functional partner(s); context anchor vapC49
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003382|Rv3181c|
MQLGRKVTSHHDIDRFGVASTADESVYRPLPPRLRLAQVNLSRRRCRTQSDMYKSRFSECTVQSVDVSVTELRAHLSDWLDRARAGGEVVITERGIPIARLAALDSTDTLERLTAEGVIGKATAQRPVAAGRPRPRPQRPVSDRVSDQRR