relG Family assigned · medium auto-curated

H37Rv Rv2866 · MTBC0 mtbc0_003048 · 87 aa · 3198488–3198751 (+) · RefSeq NP_217382.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)toxin RelG
MTBC0 PGAP re-annotationtype II toxin-antitoxin system RelE/ParE family toxin
Revised (this work)Type II toxin-antitoxin system RelE/ParE family toxin. Pfam: ParE_toxin (PF05016.22).

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

Curated reference (UniProt)

UniProt O33348 SwissProt · reviewed · Evidence at protein level
UniProt nameToxin RelG
EC (curated) EC 3.1.-.-
Curated functionToxic component of a type II toxin-antitoxin (TA) system. Has RNase activity and preferentially cleaves at the 3'-end of purine ribonucleotides (By similarity). Overexpression in M.tuberculosis or M.smegmatis inhibits colony formation in a bacteriostatic rather than bacteriocidal fashion. Its toxic effect is neutralized by coexpression with cognate antitoxin RelB2 (shown only for M.smegmatis). Overexpression also increases the number of gentamicin-tolerant and levofloxacin-tolerant persister cells..; FUNCTION: In combination with cognate antitoxin RelF represses its own promoter. Has been seen.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category K Transcription
eggNOG descriptionParE toxin of type II toxin-antitoxin system, parDE
Orthologous groupCOG2026
Gene Ontology (70) GO:0003674, GO:0003824, GO:0004518, GO:0004519, GO:0006139, GO:0006355, GO:0006401, GO:0006725, GO:0006807, GO:0008150, GO:0008152, GO:0009056 +58 more

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) 2 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
ParE_toxinPF05016.22 1.2e-125–85 ParE toxin of type II toxin-antitoxin system, parDE

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

Closest characterised functional partner: relF (antitoxin RelF), high confidence from genomic context alone (score 994 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2865 relF antitoxin RelF 998 994 ctx neighborhood:788 cooccurence:773 experimental:893 textmining:820
Rv1247c relB antitoxin RelB 956 870 ctx cooccurence:773 experimental:409 textmining:680
Rv0659c mazF2 toxin MazF2 639 576 ctx cooccurence:564
Rv1942c mazF5 toxin MazF5 596 545 ctx cooccurence:534
Rv2864c penicillin-binding lipoprotein 437 438 ctx neighborhood:436
Rv3357 relJ antitoxin RelJ 764 295 textmining:680
Rv2021c higA2 transcriptional regulator 505 218
Rv2022c higB2 hyp hypothetical protein 454 169
Rv3358 relK toxin RelK 832 77 textmining:826
Rv2034 ArsR family HTH-type transcriptional repressor 518 51 textmining:513
Rv3189 hyp hypothetical protein 516 50 textmining:512
Rv3188 hyp hypothetical protein 514 47 textmining:511
Rv2867c GCN5-like N-acetyltransferase 658 46 textmining:657
Rv0918 hyp hypothetical protein 492 46 textmining:490
Rv2451 hyp hypothetical protein 657 41 textmining:657

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: toxin RelG
  • MTBC0 PGAP product: type II toxin-antitoxin system RelE/ParE family toxin
  • Pfam (hmmscan --cut_ga): ParE_toxin PF05016.22 (E=1e-12)
  • (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_217382.1)
  • Domains: Pfam-A via hmmscan --cut_ga — ParE_toxin (PF05016.22)
  • 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 COG2026
  • Curated reference: UniProt O33348 (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 — 15 functional partner(s); context anchor relF
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003048|Rv2866|relG
MPYTVRFTTTARRDLHKLPPRILAAVVEFAFGDLSREPLRVGKPLRRELAGTFSARRGTYRLLYRIDDEHTTVVILRVDHRADIYRR