Rv0123 Family assigned · low

H37Rv Rv0123 · MTBC0 mtbc0_000134 · 122 aa · 149022–149390 (+) · RefSeq NP_214637.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationDNA-binding protein
Revised (this work)Putative DNA-binding protein. No Pfam domain above threshold, but Foldseek matches antitoxin DNA-binding domains strongly and consistently (CopASO antitoxin prob 0.99 / TM 0.83; ParDE antitoxin; PutA HTH), pointing to a ribbon-helix-helix / antitoxin-type DNA-binding fold. Structure-based, consistent with the PGAP 'DNA-binding protein' call.

Curated reference (UniProt)

UniProt O07173 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 group28Z1X

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, 1 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).

Structural neighbours (Foldseek on the ESMFold model, exploratory)

ESMFold model confidence: mean pLDDT 57.6 (low). Low-confidence model: the fold may be unreliable, so treat these structural hits with caution.

Best matches against the PDB, ranked by Foldseek homology probability. A high probability / TM-score suggests a shared fold; unless flagged sig (E < 0.01) these are fold hypotheses, not assignments.

TargetProbTME-valueDescription
6iya-assembly2_C 0.99 0.83 1.6e-01 6iya-assembly2_C Structure of the DNA binding domain of antitoxin CopASO
6xrw-assembly1_B-2 0.96 0.80 3.7e-01 6xrw-assembly1_B-2 Chromosomal ParDE TA system from P. aeruginosa
3ft7-assembly1_A 0.94 0.79 4.3e-01 3ft7-assembly1_A Crystal structure of an extremely stable dimeric protein from sulfolobus islandicus
2gpe-assembly1_A 0.72 0.77 1.5e+00 2gpe-assembly1_A Structure of the DNA-binding domain of E. Coli Proline Utilization A (PUTA)
8ypj-assembly1_A 0.66 0.66 1.0e+00 8ypj-assembly1_A Cyrstal structure of the MazE-mt10 Antitoxin from Mycobacterium tuberculosis
2k5j-assembly1_B 0.57 0.65 7.4e-01 2k5j-assembly1_B Solution structure of protein yiiF from Shigella flexneri serotype 5b (strain 8401) . Northeast Structural Genomics Consortium target sft1
8u12-assembly1_A 0.51 0.67 1.7e+00 8u12-assembly1_A Crystal Structure of Antitoxin Protein Rv0298 of Type II Toxin-antitoxin Systems from Mycobacterium tuberculosis
6sbw-assembly1_A 0.35 0.72 3.6e+00 6sbw-assembly1_A CdbA Form One

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

Closest characterised functional partner: PE_PGRS2 (PE-PGRS family protein PE_PGRS2), medium confidence from genomic context alone (score 405 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv0122 hyp hypothetical protein 887 887 ctx neighborhood:882
Rv0121c hyp hypothetical protein 533 533 ctx neighborhood:532
Rv0124 PE_PGRS2 PE-PGRS family protein PE_PGRS2 406 405 ctx neighborhood:405

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

  • MTBC0 PGAP product: 'DNA-binding protein'
  • Pfam: no domain above threshold
  • Foldseek on the ESMFold model: consistent hits to antitoxin DNA-binding domains (6IYA CopASO prob 0.99 TM 0.83; ParDE; PutA HTH) -- a DNA-binding fold

ESM Atlas signal (exploratory)

Ancestral protein hash 6d93c8d3df3504116923c5bb3be78ee0 · 10 ESM-space neighbours (max similarity 0.956). SAE features are orienting indices, not validated domains.

#IndexActivationInterpretation
18116 1.42 Terminal disorder and cap motifs
214869 1.11 N-terminal basic DNA-binding patch
36413 0.93 Basic amphipathic interface patches
4952 0.91 Basic phosphate-binding DNA/RNA/CoA patches
513077 0.89 Short basic amphipathic recognition helices
69286 0.89 Short amphipathic alpha-helix motif
75762 0.84 Charged low-complexity terminal/linker IDRs
89860 0.76 Amphipathic helix N-cap motifs

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_214637.1)
  • 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 28Z1X
  • Curated reference: UniProt O07173 (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)
  • Model confidence: ESMFold per-residue pLDDT (mean 57.6, low)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 3 functional partner(s); context anchor PE_PGRS2
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000134|Rv0123|
MTKKPRNPADYVIGDDVEVSDVDLKQEEVYVDGERLTDERVEQMASESLRLAREREANLIPGGKSLSGGSAHSPAVQVVVSKATHAKLKELARSRKMSVSKLLRPVLDEFVQRETGRILPRR