Rv2468c Resolved · medium

H37Rv Rv2468c · MTBC0 - · 167 aa · 2771644–2772147 (-) · RefSeq NP_216984.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotation
Revised (this work)Immunomodulatory / T-cell costimulatory protein: binds integrin VLA-5 (alpha5beta1) via an RGD motif and costimulates T cells. NOTE: a Foldseek hit to the cytochrome bcc:aa3 fold is a FALSE POSITIVE (the Mtb cytochrome bcc is qcrCAB, not this gene).

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 P9WLA7 SwissProt · reviewed · Evidence at protein level
UniProt nameUncharacterized protein Rv2468c

UniProt still lists this protein as Uncharacterized protein Rv2468c; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
eggNOG descriptionDomain of unknown function (DUF5130)
Orthologous groupCOG1512
Gene Ontology (6) GO:0005575, GO:0005623, GO:0005886, GO:0016020, GO:0044464, GO:0071944

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, 3 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
DUF5130PF17174.11 1.8e-6526–161 Domain of unknown function (DUF5130)

Structural neighbours (Foldseek on the ESMFold model, exploratory)

ESMFold model confidence: mean pLDDT 68.7 (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
8hcr-assembly1_V 1.00 0.80 2.4e-18 sig 8hcr-assembly1_V Cryo-EM structure of the Mycobacterium tuberculosis cytochrome bcc:aa3 supercomplex and a novel inhibitor targeting subunit cytochrome cI
9dm1-assembly1_V 1.00 0.80 3.9e-16 sig 9dm1-assembly1_V Mycobacterial supercomplex malate:quinone oxidoreductase assembly
6hwh-assembly2_O 1.00 0.80 1.8e-14 sig 6hwh-assembly2_O Structure of a functional obligate respiratory supercomplex from Mycobacterium smegmatis
5anp-assembly2_B 1.00 0.81 4.8e-04 sig 5anp-assembly2_B CRYSTAL STRUCTURE OF THE BA41 PROTEIN FROM BIZIONIA ARGENTINENSIS
3pw9-assembly1_A 1.00 0.79 9.0e-04 sig 3pw9-assembly1_A Structural and functional Analysis of Arabidopsis thaliana thylakoid lumen protein AtTLP18.3
5anp-assembly1_A 1.00 0.72 5.7e-04 sig 5anp-assembly1_A CRYSTAL STRUCTURE OF THE BA41 PROTEIN FROM BIZIONIA ARGENTINENSIS
3ptj-assembly1_A 1.00 0.79 1.7e-03 sig 3ptj-assembly1_A Structural and functional Analysis of Arabidopsis thaliana thylakoid lumen protein AtTLP18.3
2kpt-assembly1_A 1.00 0.78 2.9e-03 sig 2kpt-assembly1_A Solution NMR structure of the N-terminal domain of cg2496 protein from Corynebacterium glutamicum. Northeast Structural Genomics Consortium Target CgR26A

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

Closest characterised functional partner: qcrA (ubiquinol-cytochrome C reductase rieske iron-sulfur subunit), high confidence from genomic context alone (score 893 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv2468A hyp hypothetical protein 936 937 ctx neighborhood:882 experimental:484
Rv2195 qcrA ubiquinol-cytochrome C reductase rieske iron-sulfur subunit 893 893 ctx cooccurence:544 experimental:747
Rv2199c ctaF cytochrome c oxidase polypeptide 4 829 829 experimental:747
Rv2200c ctaC cytochrome C oxidase subunit II 819 819 experimental:783
Rv2196 qcrB ubiquinol-cytochrome C reductase cytochrome subunit B 816 816 experimental:783
Rv1638A hyp hypothetical protein 816 812 ctx cooccurence:745
Rv2469c hyp hypothetical protein 811 812 ctx neighborhood:811
Rv2744c 35kd_ag hyp hypothetical protein 810 807 ctx cooccurence:738
Rv3043c ctaD cytochrome C oxidase cytochrome 1 793 794 experimental:783
Rv2194 qcrC ubiquinol-cytochrome C reductase cytochrome subunit C 791 792 experimental:747
Rv2179c 3'-5' exoribonuclease 764 764 ctx cooccurence:764
Rv2193 ctaE cytochrome C oxidase subunit III 750 750 experimental:747
Rv2520c membrane protein 749 750 ctx cooccurence:745
Rv1222 rseA anti-sigma E factor RseA 749 749 ctx cooccurence:740
Rv1109c hyp hypothetical protein 747 747 ctx cooccurence:741

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

  • Experimentally characterised as a T-cell costimulatory protein (RGD/VLA-5) by Li et al. 2012
  • Structural cytochrome bcc:aa3 hit refuted: that complex is encoded by qcrCAB

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_216984.1)
  • Domains: Pfam-A via hmmscan --cut_ga — DUF5130 (PF17174.11)
  • 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 COG1512
  • Curated reference: UniProt P9WLA7 (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)
  • Model confidence: ESMFold per-residue pLDDT (mean 68.7, low)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 95 functional partner(s); context anchor qcrA
  • Primary literature: Li J, Ding BY, Thomas WD, et al. (2012). A T-cell costimulatory molecule of Mycobacterium tuberculosis J Leukoc Biol. doi:10.1189/jlb.0711364 PMID:22158781

Ancestral MTBC0 protein sequence

>H37Rv|Rv2468c|
MTHRSSRLEVGPVARGDVATIEHAELPPGWVLTTSGRISGVTEPGELSVHYPFPIADLVALDDALTYSSRACQVRFAIYLGDLGRDTAARAREILGKVPTPDNAVLLAVSPNQCAIEVVYGSQVRGRGAESAAPLGVAAASSAFEQGELVDGLISAIRVLSAGIAPG