relB Family assigned · medium auto-curated

H37Rv Rv1247c · MTBC0 mtbc0_001336 · 89 aa · 1397419–1397688 (-) · RefSeq NP_215763.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)antitoxin RelB
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 O50462 SwissProt · reviewed · Evidence at protein level
UniProt nameAntitoxin RelB
Curated functionAntitoxin component of a type II toxin-antitoxin (TA) system. Upon expression in M.smegmatis neutralizes the effect of toxin RelE..; FUNCTION: Induces its own promoter, in combination with RelE represses its own promoter. Binds DNA in complex with toxin RelE but not alone.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category K Transcription
Preferred namerelB
eggNOG descriptionantitoxin component of a
Orthologous groupCOG2161
KEGG orthology K19159
Gene Ontology (10) GO:0003674, GO:0005488, GO:0005515, GO:0008150, GO:0040008, GO:0045927, GO:0048518, GO:0050789, GO:0065007, GO:0097351

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 0.0 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 0 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-221–73 Antitoxin Phd_YefM, type II toxin-antitoxin system

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

Closest characterised functional partner: relE (toxin RelE), high confidence from genomic context alone (score 983 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1246c relE toxin RelE 997 983 ctx neighborhood:882 cooccurence:774 textmining:878
Rv2866 relG toxin RelG 956 870 ctx cooccurence:773 experimental:409 textmining:680
Rv3358 relK toxin RelK 956 765 experimental:748 textmining:824
Rv1245c short-chain type dehydrogenase/reductase 652 652 ctx neighborhood:651
Rv0659c mazF2 toxin MazF2 665 642 ctx cooccurence:635
Rv1942c mazF5 toxin MazF5 626 611 ctx cooccurence:604
Rv1248c kgd multifunctional 2-oxoglutarate dehydrogenase E1 component /2-oxoglutarate dehydrogenase dihydrolipoyllysine-residue succinyltransferase 577 577 ctx neighborhood:564
Rv0960 vapC9 ribonuclease VapC9 504 428 ctx cooccurence:406
Rv1720c vapC12 ribonuclease VapC12 409 389
Rv1102c mazF3 mRNA interferase MazF3 461 355
Rv2017 transcriptional regulator 424 352
Rv0595c vapC4 ribonuclease VapC4 459 321
Rv2801A mazE9 antitoxin MazE9 569 270 textmining:434
Rv2549c vapC20 ribonuclease VapC20 410 167
Rv0350 dnaK chaperone protein DnaK 528 55 textmining:522

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 RelB
  • MTBC0 PGAP product: type II toxin-antitoxin system Phd/YefM family antitoxin
  • Pfam (hmmscan --cut_ga): PhdYeFM_antitox PF02604.27 (E=1e-22)
  • (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_215763.1)
  • 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 COG2161
  • Curated reference: UniProt O50462 (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 — 20 functional partner(s); context anchor relE
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001336|Rv1247c|relB
MAVVPLGEVRNRLSEYVAEVELTHERITITRHGHPAAVLISADDLASIEETLEVLRTPGASEAIREGLADVAAGRFVSNDEIRNRYTAR