Rv2018 Family assigned · medium auto-curated

H37Rv Rv2018 · MTBC0 mtbc0_002148 · 239 aa · 2288893–2289612 (+) · RefSeq NP_216534.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationDUF433 domain-containing protein
Revised (this work)DUF433 domain-containing protein. Pfam: HTH_66 (PF21321.4), DUF433 (PF04255.21).

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

Curated reference (UniProt)

UniProt O53464 SwissProt · reviewed · Evidence at protein level
UniProt namePutative antitoxin VapB45
Curated functionPossibly the antitoxin component of a type II toxin-antitoxin (TA) system. Its cognate toxin is VapC45.

UniProt still lists this protein as Putative antitoxin VapB45; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
eggNOG descriptionProtein of unknown function (DUF433)
Orthologous groupCOG2442

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 0.139 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 5 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
HTH_66PF21321.4 9.5e-3114–96 Putative DNA-binding HTH domain
DUF433PF04255.21 3.9e-10183–234 Protein of unknown function (DUF433)

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

Closest characterised functional partner: vapB49 (antitoxin VapB45), medium confidence from genomic context alone (score 552 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv2019 vapC45 hyp hypothetical protein 890 803 ctx neighborhood:802 textmining:464
Rv3181c vapB49 antitoxin VapB45 785 552 ctx cooccurence:551 textmining:540
Rv0582 vapC26 ribonuclease VapC26 546 547 ctx cooccurence:545
Rv0960 vapC9 ribonuclease VapC9 534 523 ctx cooccurence:522
Rv2231A vapC16 ribonuclease VapC16 517 516 ctx cooccurence:516
Rv0617 vapC29 ribonuclease VapC29 505 506 ctx cooccurence:502
Rv3320c vapC44 ribonuclease VapC44 502 502 ctx cooccurence:500
Rv2494 vapC38 ribonuclease VapC38 510 497 ctx cooccurence:492
Rv2735c hyp hypothetical protein 488 489 ctx cooccurence:488
Rv3098A PemK-like protein 488 488 ctx cooccurence:488
Rv2530c vapC39 ribonuclease VapC39 482 482 ctx cooccurence:480
Rv2016 hyp hypothetical protein 470 470 ctx neighborhood:443
Rv2017 transcriptional regulator 688 469 ctx neighborhood:456 textmining:438
Rv1004c membrane protein 466 467 ctx cooccurence:464
Rv0304c PPE5 PPE family protein PPE5 459 460 ctx cooccurence:457

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: hypothetical protein
  • MTBC0 PGAP product: DUF433 domain-containing protein
  • Pfam (hmmscan --cut_ga): HTH_66 PF21321.4 (E=1e-30), DUF433 PF04255.21 (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_216534.1)
  • Domains: Pfam-A via hmmscan --cut_ga — HTH_66 (PF21321.4), DUF433 (PF04255.21)
  • 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 COG2442
  • Curated reference: UniProt O53464 (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 vapB49
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002148|Rv2018|
MAGDQELELRFDVPLYTLAEASRYLVVPRATLATWADGYERRPANAPAVQGQPIITALPHPTGSHARLPFVGIAEAYVLNAFRRAGVPMQRIRPSLDWLIKNVGPHALASQDLCTDGAEVLWRFAERSGEGSPDDLVVRGLIVPRSGQYVFKEIVEHYLQQISFADDNLASMIRLPQYGDANVVLDPRRGYGQPVFDGSGVRVADVLGPLRAGATFQAVADDYGVTPDQLRDALDAIAA