Rv3491 Family assigned · medium

H37Rv Rv3491 · MTBC0 mtbc0_003706 · 192 aa · 3934472–3935050 (+) · RefSeq NP_218008.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationhypothetical protein
Revised (this work)Membrane-anchored protein with a PknI-sensor-domain-like extracytoplasmic sensor fold; distinct from PknI/Rv2914c (fold-paralogue safeguard); ligand/partner undetermined RefSeq leaves this locus uncharacterised.

Curated reference (UniProt)

UniProt I6XHD1 TrEMBL · unreviewed · Evidence at protein level
UniProt nameSecreted protein

Functional vocabulary (eggNOG-mapper, orthology transfer)

Orthologous group2AQE9

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 0.08 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 4 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 79.8 (confident). A confident model makes the fold comparison meaningful.

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
8ass-assembly2_C 0.80 0.50 2.4e-01 8ass-assembly2_C The Crystal structure of F46Y mutant of the agroavidin-biotin complex
1iiu-assembly1_A 0.38 0.38 3.4e-01 1iiu-assembly1_A Chicken plasma retinol-binding protein (RBP)
4h8p-assembly1_A 0.33 0.31 1.3e-01 4h8p-assembly1_A NEAT5 domain of IsdX2, a B. anthracis hemophore in complex with heme
4h8q-assembly1_A 0.23 0.32 2.9e-01 4h8q-assembly1_A Structure of the Q29T IsdX2-NEAT5 mutant in complex with heme
1l3a-assembly1_C 0.13 0.29 9.9e-01 1l3a-assembly1_C Structure of the plant transcriptional regulator PBF-2
2lfu-assembly1_A 0.11 0.30 1.2e+00 2lfu-assembly1_A The structure of a N. meningitides protein targeted for vaccine development
1qab-assembly1_F 0.11 0.33 1.9e+00 1qab-assembly1_F The structure of human retinol binding protein with its carrier protein transthyretin reveals interaction with the carboxy terminus of RBP
8huy-assembly1_B 0.10 0.20 1.3e-01 8huy-assembly1_B N-acetyl-(R)-beta-phenylalanine acylase

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

Closest characterised functional partner: otsA (trehalose-phosphate synthase), medium confidence from genomic context alone (score 559 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv2006 otsB1 trehalose-6-phosphate phosphatase OtsB 821 747 coexpression:651
Rv3372 otsB2 trehalose 6-phosphate phosphatase 737 692 coexpression:650
Rv3490 otsA trehalose-phosphate synthase 559 559 ctx neighborhood:539
Rv3489 hyp hypothetical protein 523 523 ctx neighborhood:511
Rv1954A Rv1954A, len: 100 aa. Hypothetical unknown protein. 432 432 coexpression:432
Rv2771c hyp hypothetical protein 418 419 coexpression:418
Rv0007 membrane protein 415 416 coexpression:416
Rv0888 spmT hyp hypothetical protein 412 413 coexpression:413
Rv1884c rpfC resuscitation-promoting factor RpfC 431 410 coexpression:410
Rv1449c tkt transketolase 407 408 coexpression:408
Rv0925c hyp hypothetical protein 404 405 coexpression:404
Rv2450c rpfE resuscitation-promoting factor RpfE 424 403 coexpression:403
Rv3835 hyp hypothetical protein 809 74 textmining:803
Rv2799 membrane protein 873 70 textmining:870
Rv1887 hyp hypothetical protein 757 57 textmining:753

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 (Neff 6.07, signal peptide+TM): top hit 5XLM_B PknI extracellular sensor domain Prob 99.6%, E 3.2e-14, 125 cols (also 5XLL); NOT PknI (=Rv2914c); same sensor fold as Rv2253
  • 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_218008.1)
  • 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 2AQE9
  • Curated reference: UniProt I6XHD1 (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 79.8, confident)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 24 functional partner(s); context anchor otsA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003706|Rv3491|
MNIRCGLAAGAVICSAVALGIALHSGDPARALGPPPDGSYSFNQAGVSGVTWTITALCDQPSGTRNMNDYSDPIVWAFNCALNVVSTTPQQITRTDRLQNFSGRARMSSMLWTFQVNQADGVACPDGSTAPSSETYAFSDETLTGTHTTVHGAVCGLQPKLSKQPFSLQLIGPPPSPVQRYPLYCNNIAMCY