Rv0349 Family assigned · low

H37Rv Rv0349 · MTBC0 - · 219 aa · 418949–419608 (+) · RefSeq NP_214863.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotation
Revised (this work)MazF/PemK-family ribonuclease fold (candidate toxin of a type II toxin-antitoxin system). RefSeq leaves it 'hypothetical protein'. The AlphaFold model superposes on MazF (PDB 9g2g; Foldseek prob 1.0, TM 0.72). A distinct locus from the named M. tuberculosis MazF paralogues. Fold-level TA-toxin assignment; the cognate antitoxin and cleavage specificity are undemonstrated.

Annotated on the H37Rv protein: this gene has no 1:1 ancestral MTBC0 anchor (PE/PPE, paralogue, IS element, or otherwise unanchored CDS).

Curated reference (UniProt)

UniProt O06300 TrEMBL · unreviewed · Evidence at protein level
UniProt nameUncharacterized protein

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

Functional vocabulary (eggNOG-mapper, orthology transfer)

Orthologous group2D5EC

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 n/a
Polymorphic sites (≥ 0.1% of strains) 0 synonymous, 4 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)

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

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

Closest characterised functional partner: Rv0347 (membrane protein), high confidence from genomic context alone (score 833 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv0347 membrane protein 834 833 ctx neighborhood:801
Rv0348 mosR transcriptional regulator 810 810 ctx neighborhood:809
Rv0350 dnaK chaperone protein DnaK 465 465 ctx neighborhood:462
Rv0351 grpE stress response protein GrpE 465 465 ctx neighborhood:462
Rv0353 hspR heat shock protein transcriptional repressor HspR 400 400
Rv0352 dnaJ1 chaperone protein DnaJ 400 400

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

  • Foldseek -> MazF ribonuclease (9g2g), prob 1.0, TM 0.72
  • Distinct from named mazF paralogues
  • Structural homology: AlphaFold DB model + Foldseek vs PDB (project 'Still unknown gene function', phase5-7, 2026-06-10). A fold-level family assignment, not a demonstrated activity.

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_214863.1)
  • 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 2D5EC
  • Curated reference: UniProt O06300 (TrEMBL, unreviewed; 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 — 6 functional partner(s); context anchor Rv0347
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv0349|
MPELETPDDPESIYLARLEDVGEHRPTFTGDIYRLGDGRMVMILQHPCALRHGVDLHPRLLVAPVRPDSLRSNWARAPFGTMPLPKLIDGQDHSADFINLELIDSPTLPTCERIAVLSQSGVNLVMQRWVYHSTRLAVPTHTYSDSTVGPFDEADLIEEWVTDRVDDGADPQAAEHECASWLDERISGRTRRALLSDRQHASSIRREARSHRKSVKLAD