arfC Family assigned · medium auto-curated

H37Rv Rv0901 · MTBC0 mtbc0_000955 · 175 aa · 1007171–1007698 (+) · RefSeq NP_215416.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)membrane protein
MTBC0 PGAP re-annotationhypothetical protein
Revised (this work)Contains ArfC (PF27542.1) domain(s); putative function inferred from the domain architecture.

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

Curated reference (UniProt)

UniProt P9WJG5 SwissProt · reviewed · Evidence at protein level
UniProt nameUncharacterized membrane protein ArfC
Curated functionRequired for wild-type expression of ArfA and ammonia secretion, not however part of an ammonia transporter. Is highly immunogenic and may play a role in virulence.

UniProt still lists this protein as Uncharacterized membrane protein ArfC; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

Orthologous group2DDPV
KEGG orthology K16193

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 0.698 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 3 synonymous, 6 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
ArfCPF27542.1 5.8e-25107–167 ArfC

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

Closest characterised functional partner: arfA (peptidoglycan-binding protein ArfA), high confidence from genomic context alone (score 905 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0899 arfA peptidoglycan-binding protein ArfA 986 905 ctx neighborhood:869 textmining:861
Rv0900 arfB membrane protein 984 885 ctx neighborhood:882 textmining:870
Rv3879c espK ESX-1 secretion-associated protein EspK 654 654 ctx cooccurence:654
Rv1651c PE_PGRS30 PE-PGRS family protein PE_PGRS30 610 610 ctx cooccurence:610
Rv0898c hyp hypothetical protein 605 606 ctx neighborhood:606
Rv0977 PE_PGRS16 PE-PGRS family protein PE_PGRS16 577 577 ctx cooccurence:577
Rv3882c eccE1 ESX-1 secretion system protein EccE1 570 571 ctx cooccurence:570
Rv3877 eccD1 ESX-1 secretion system protein EccD1 569 569 ctx cooccurence:568
Rv0341 iniB isoniazid inducible protein IniB 561 561 ctx cooccurence:561
Rv3737 transmembrane protein 546 547 ctx cooccurence:544
Rv0872c PE_PGRS15 PE-PGRS family protein PE_PGRS15 544 544 ctx cooccurence:544
Rv1226c transmembrane protein 528 528 ctx cooccurence:526
Rv2209 integral membrane protein 519 520 ctx cooccurence:517
Rv0897c oxidoreductase 519 519 ctx neighborhood:514
Rv2608 PPE42 PPE family protein PPE42 517 517 ctx cooccurence:514

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: membrane protein
  • MTBC0 PGAP product: hypothetical protein
  • Pfam (hmmscan --cut_ga): ArfC PF27542.1 (E=6e-25)
  • (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_215416.1)
  • Domains: Pfam-A via hmmscan --cut_ga — ArfC (PF27542.1)
  • 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 2DDPV
  • Curated reference: UniProt P9WJG5 (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 — 41 functional partner(s); context anchor arfA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000955|Rv0901|arfC
MEHVHWWLAGLAFTLGMVLTSTLMVRPVEHQVLVKKSVRGSSAKSKPPTARKPAVKSGTKREESPTAKTKVATESAAEQIPVAGEPAAEPIPVAGEPAARIPVVPYAPYGPGSARAGADGSGPQGWLVKGRSDTRLYYTPEDPTYDPTVAQVWFQDEESAARAFFTPWRKSTRRT