vapC19 Family assigned · medium auto-curated

H37Rv Rv2548 · MTBC0 mtbc0_002715 · 125 aa · 2892405–2892782 (+) · RefSeq NP_217064.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)ribonuclease VapC19
MTBC0 PGAP re-annotationtype II toxin-antitoxin system VapC family toxin
Revised (this work)Type II toxin-antitoxin system VapC family toxin. Pfam: PIN (PF01850.28).

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

Curated reference (UniProt)

UniProt P9WF93 SwissProt · reviewed · Evidence at protein level
UniProt nameRibonuclease VapC19
EC (curated) EC 3.1.-.-
Curated functionToxic component of a type II toxin-antitoxin (TA) system. An RNase (By similarity). Upon expression in M.smegmatis inhibits colony formation. Its toxic effect is neutralized by coexpression with cognate antitoxin VapB19.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
eggNOG descriptionPIN domain
Orthologous groupCOG1487

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

PfamAccessioni-EvalueResiduesDescription
PINPF01850.28 9.9e-123–111 PIN domain

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

Closest characterised functional partner: vapB19 (antitoxin VapB19), high confidence from genomic context alone (score 884 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2547 vapB19 antitoxin VapB19 941 884 ctx neighborhood:882 textmining:518
Rv2546 vapC18 ribonuclease VapC18 740 740 ctx neighborhood:739
Rv2545 vapB18 antitoxin VapB18 588 589 ctx neighborhood:508
Rv0277c vapC25 ribonuclease VapC25 736 493 ctx cooccurence:489 textmining:502
Rv0749 vapC31 ribonuclease VapC31 693 490 ctx cooccurence:485 textmining:423
Rv3098A PemK-like protein 480 479 ctx cooccurence:476
Rv2544 lppB lipoprotein LppB 475 476 ctx neighborhood:473
Rv2543 lppA lipoprotein LppA 464 464 ctx neighborhood:458
Rv2063A mazF7 mRNA interferase MazF7 452 451 ctx cooccurence:448
Rv2103c vapC37 ribonuclease VapC37 747 449 ctx cooccurence:438 textmining:561
Rv2872 vapC43 ribonuclease VapC43 653 432 ctx cooccurence:430 textmining:414
Rv0626 vapB5 antitoxin VapB5 432 432
Rv0300 vapB2 antitoxin VapB2 430 430 experimental:412
Rv2807 hyp hypothetical protein 424 425 ctx cooccurence:423
Rv2549c vapC20 ribonuclease VapC20 718 420 ctx cooccurence:408 textmining:534

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: ribonuclease VapC19
  • MTBC0 PGAP product: type II toxin-antitoxin system VapC family toxin
  • Pfam (hmmscan --cut_ga): PIN PF01850.28 (E=1e-11)
  • (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_217064.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PIN (PF01850.28)
  • 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 COG1487
  • Curated reference: UniProt P9WF93 (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 — 49 functional partner(s); context anchor vapB19
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002715|Rv2548|vapC19
MKLIDTTIAVDHLRGEPAAAVLLAELINNGEEIAASELVRFELLAGVRESELAALEAFFSAVVWTLVTEDIARIGGRLARRYRSSHRGIDDVDYLIAATAIVVDADLLTTNVRHFPMFPDLQPPY