Rv1678 Family assigned · low

H37Rv Rv1678 · MTBC0 mtbc0_001786 · 300 aa · 1914412–1915314 (+) · RefSeq NP_216194.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)integral membrane protein
MTBC0 PGAP re-annotationhypothetical protein
Revised (this work)Polytopic integral membrane protein with a GT-C-like / membrane-enzyme-chaperone fold; weakly linked to M.tb Emb arabinosyltransferases (cell-wall GT-C family); specific function undetermined RefSeq leaves this locus uncharacterised.

Curated reference (UniProt)

UniProt O53925 TrEMBL · unreviewed · Predicted
UniProt nameProbable integral membrane protein

Functional vocabulary (eggNOG-mapper, orthology transfer)

Orthologous group2EA1Q

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 0.284 · purifying
Polymorphic sites (≥ 0.1% of strains) 7 synonymous, 4 missense, 1 nonsense, 0 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 0.85% of strains (1236) · clonal

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)

No Pfam-A domain above the gathering threshold (or not yet scanned).

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

Closest characterised functional partner: fadE16 (acyl-CoA dehydrogenase FadE16), high confidence from genomic context alone (score 982 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1679 fadE16 acyl-CoA dehydrogenase FadE16 982 982 ctx neighborhood:881 coexpression:855
Rv1681 moeX molybdopterin biosynthesis protein MoeX 977 978 ctx neighborhood:879 coexpression:826
Rv1680 hyp hypothetical protein 976 977 ctx neighborhood:879 coexpression:815
Rv1676 hyp hypothetical protein 564 563 ctx neighborhood:540
Rv1677 dsbF lipoprotein DsbF 556 555 ctx neighborhood:532
Rv1682 hyp hypothetical protein 505 506 ctx neighborhood:483
Rv1675c cmr HTH-type transcriptional regulator Cmr 424 423

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

  • HHpred: top hit 9H9E membrane-protein chaperone Prob 98.5%, E 2e-6, 98 cols; vitamin-K gamma-carboxylase (GT-C-like) 95.9%; weak EmbC/EmbA arabinosyltransferases (M.tb cell wall) 42/27%
  • HHpred web (MPI Bioinformatics Toolkit, profile-profile remote homology), interpreted in project 'Still unknown gene function', 2026-06-10. A fold/family-level assignment, not a demonstrated function.

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_216194.1)
  • Domains: Pfam-A via hmmscan --cut_ga — none above threshold
  • 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 2EA1Q
  • Curated reference: UniProt O53925 (TrEMBL, unreviewed; Predicted)
  • 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 — 7 functional partner(s); context anchor fadE16
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001786|Rv1678|
MARVRRGTELLLSPQSPPATGGLIVLTGLRLLAGLIWLYNVVWKVPPDFGERGRRDLYHFTHLAVEHPVFTPFSWVIEHAVLPYFTAFGWGVLFAESALAVLLLTGTAVRLAALIGIGQSVAIGLSVAESPGEWPWAYAMLLGIHVVLLFTCSTRYAAVDAVRAAATGSAARTAAQRLLAGWGIVLGLIGLVAVWRGLGDDRPAYVGIRALEFSLGEYNLRGALALIAIALAMLAAAKRGWRTVALVAAVVAVAAAAAIYLQVGRTAVWLGGTNTTAAVFVCAAVVSLATEFRIGRVEGA