Rv2141c Family assigned · medium auto-curated

H37Rv Rv2141c · MTBC0 - · 448 aa · 2400376–2401722 H37Rv (-) · RefSeq YP_177864.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotation
Revised (this work)Contains Peptidase_M28 (PF04389.23), Peptidase_M20 (PF01546.34), M20_dimer (PF07687.20) domain(s); putative function inferred from the domain architecture.
Functional category (TubercuList)intermediary metabolism and respiration

Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.

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

In the literature (TB corpus sweep) 1 publication

Found under: H37Rv (1).

1 TB publication mentions this gene. 1 publication(s) mention this gene (title/abstract), verified against the text. The atlas states the function; these are the primary sources that discuss it.

PublicationDate
Label-Free Comparative Proteomics of Differentially Expressed Mycobacterium tuberculosis Protein in Rifampicin-Related Drug-Resistant Strains. doi:10.3390/pathogens10050607 2021

This layer CITES the literature, it does not change the verdict or the function. A gene may be heavily studied (as an antigen, a resistance determinant, a drug target) while its molecular function is settled elsewhere in the fiche. This distinguishes a gene that is dark because nobody has looked from one that is dark despite having been studied. Source: PubMed (whole), MULTI-ALIAS sweep: H37Rv locus tag AND every ortholog identifier (M. bovis Mb…, M. marinum MMAR_…, M. smegmatis MSMEG_…, M. leprae ML…, M. abscessus MAB_…), each hit VERIFIED against the abstract text (word-boundary regex). phase73/phase75, 2026-07-13.

CRISPRi vulnerability

Vulnerability index 1.04 (95% CI -0.89 to 3.97). A more negative index = more vulnerable to knockdown (better drug-target quality); indicative threshold VI ≤ -6 = highly vulnerable.

Quantitative CRISPRi knockdown, graded (finer than binary Tn-seq essentiality). Source: CRISPRi vulnerability index (Bosch 2021, pebble.rockefeller.edu).

Orthologues (reciprocal best hits across mycobacteria)

M. bovis Mb2165c · 99.8% identity
M. leprae ML1288 · 84.2% identity
M. marinum MMAR_3123 · 87.9% identity
M. smegmatis MSMEG_4200 · 76.6% identity
M. orygis RJtmp_002210 · 99.8% identity
M. abscessus MAB_2102 · 77.4% identity

Reciprocal-best-hit orthologues (DIAMOND) against the Mycobrowser reference proteomes. A missing species is informative: e.g. a gene absent from M. leprae was likely lost in its reductive genome evolution. Locus tags link to Mycobrowser.

Curated reference (UniProt)

UniProt L7N684 TrEMBL · unreviewed · Evidence at protein level
UniProt nameConserved protein

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

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category E Amino acid transport and metabolism
Preferred namedapE2
eggNOG descriptiondeacetylase Succinyl-diaminopimelate desuccinylase and related deacylases
Orthologous groupCOG0624

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 1.179 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 7 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.

Outgroup conservation (beyond the MTBC) Actinomycetia

M. canettii dN/dS (deep-divergence selection) inf (low power) · 2 consensus substitution(s)
low power (2 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable
Genus-wide presence (~53 non-MTBC Mycobacterium) present in 53/53 (100%) · mean identity 85.2% · 4/4 closest MTBAP relatives
conserved across the genus (present in 53/53 non-MTBC Mycobacterium genomes, incl. distant relatives) — an ancient core gene predating the genus radiation
Phylostratum (deepest detected homolog) MTBC-specific Mycobacterium Mycobacteriaceae Corynebacteriales Actinomycetia Bacteria
detected in 10/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 57.4%
detected across the class Actinomycetia (beyond Corynebacteriales) but not outside the phylum — an Actinobacteria-level ancient gene

Two orthogonal outgroup signals. M. canettii (the immediate outgroup) gives a deep-divergence dN/dS (a low value confirms a constrained, real gene; shown as confident only at ≥8 substitutions, else flagged low-power). Genus-wide presence/absence (tblastn vs assembled non-MTBC genomes) places the gene on the ancient-core ↔ MTBC-specific axis: a gene absent even from the closest MTBAP relatives is a candidate MTBC-specific innovation (possible host-adaptation factor, to confirm by synteny). The phylostratum extends that axis outside the genus (tblastn vs 13 reference genomes spanning Mycobacteriaceae → Corynebacteriales → Actinomycetia → outside the phylum): it is the deepest clade in which a homolog is still detected, i.e. a proxy for gene age. Read it with the null model in mind: a shallow (young) stratum can also reflect homology-detection failure for short or fast-evolving ORFs, so it is a descriptive axis, not a proof of novelty.

Essentiality (transposon mutagenesis)

DeJesus 2017 callNE · non-essential
What the call meansnon-essential
TA sites (Himar1) 22 in the ORF — 0 in the essential state, 0 growth-defect, 22 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 151.090909091. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction.

Genome-wide Himar1 transposon essentiality in H37Rv (DeJesus 2017). An essential call (ES/ESD/GD) is strong, independent evidence that a "hypothetical" locus encodes a functional, selectively required gene — orthogonal to intra-species conservation.

Proteomics (mass spectrometry) detected

MS detectiondetected in 15 of 16 independent MS datasets
Integrated abundance510.0 ppm · rank 395/3519 (88.8th percentile)

Detection by mass spectrometry is direct, experimental evidence that the protein product exists — orthogonal to sequence conservation and to Tn-seq essentiality, and especially decisive for a "hypothetical" locus. Reproducible detection across several independent datasets (PaxDb) makes the existence claim robust; the integrated abundance places the protein in the proteome's dynamic range.

Predicted localisation (DeepTMHMM + lipobox) signal peptide

Predictionpredicted secreted protein (signal peptide)
DeepTMHMM classSP

Transmembrane topology and signal peptide from DeepTMHMM (deep-learning reference predictor); lipoproteins from a (myco)bacterial lipobox motif. A sequence-based prediction of subcellular context.

Physico-chemical properties (computed, ProtParam)

Length448 aa
Molecular weight48.1 kDa
Theoretical pI4.93
GRAVY-0.053 (hydrophilic)
Aliphatic index86.0
Aromaticity0.071
Instability index26.3 (stable)

Computed from the ancestral MTBC0 sequence with the ExPASy ProtParam method (Biopython). Descriptive biophysical context: a positive GRAVY flags a hydrophobic (often membrane) protein, a high instability index (>40) predicts a short in-vitro half-life, an extreme pI hints at compartment or binding partner.

Domains (Pfam, hmmscan --cut_ga)

PfamAccessioni-EvalueResiduesDescription
Peptidase_M28PF04389.23 8.9e-1069–169 Peptidase family M28
Peptidase_M20PF01546.34 5.2e-3185–446 Peptidase family M20/M25/M40
M20_dimerPF07687.20 3.3e-14206–332 Peptidase dimerisation domain

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 94.4

PDB hitprobTM-scoreE-valueDescription
7uoi-assembly1_A 1.00 0.80 2.9e-28 sig 7uoi-assembly1_A Crystallographic structure of DapE from Enterococcus faecium
5vo3-assembly1_A-2 1.00 0.78 3.9e-28 sig 5vo3-assembly1_A-2 Crystal structure of DapE in complex with the products (succinic acid and diaminopimelic acid)
2rb7-assembly1_B 1.00 0.78 2.4e-27 sig 2rb7-assembly1_B Crystal structure of co-catalytic metallopeptidase (YP_387682.1) from Desulfovibrio desulfuricans G20 at 1.60 A resolution
8f8o-assembly1_A 1.00 0.76 7.2e-27 sig 8f8o-assembly1_A Crystal Structure of the Succinyl-diaminopimelate Desuccinylase (DapE) from Acinetobacter baumannii in complex with Succinic and L-Lactic Acids
7lgp-assembly1_A 1.00 0.80 7.2e-26 sig 7lgp-assembly1_A DapE enzyme from Shigella flexneri

Foldseek search of the AlphaFold DB model (mean pLDDT 94.4, gated at 70) against the PDB — a genome-wide extension of the ESMFold dark-gene search that also covers proteins beyond the single-sequence length limit. Confident structural neighbours (E < 0.01) shown.

Genomic context (neighbours & predicted operon) operon of 2

Upstream (5' on genome)TB18.6 (- strand, 47 bp gap)
Downstream (3' on genome)leuU (+ strand, 264 bp gap)
Predicted operon TB18.6 · Rv2141c

Neighbours from the H37Rv annotation (- strand). The operon is predicted by co-directional intergenic distance (same strand, gaps ≤50 bp) — a transcription-unit hypothesis, not a mapped TSS. For a "hypothetical", co-transcription with a characterised operon is a concrete functional lead (complements the STRING neighborhood channel below).

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

Explore full network →

Node colour = verdict, dashed = hypothetical; edge colour = evidence (green experimental, orange genomic-context, grey co-expression), width ∝ score. Click a partner to open its page; "Explore full network" to walk the graph.

Closest characterised functional partner: ctaF (cytochrome c oxidase polypeptide 4), medium confidence from genomic context alone (score 492 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv2140c TB18.6 hyp hypothetical protein 832 827 ctx neighborhood:816
Rv1652 argC N-acetyl-gamma-glutamyl-phoshate reductase 545 497 coexpression:403
Rv2199c ctaF cytochrome c oxidase polypeptide 4 492 492 ctx cooccurence:473
Rv1658 argG argininosuccinate synthase 520 468
Rv3436c glmS exp glucosamine--fructose-6-phosphate aminotransferase 497 443 experimental:419
Rv2146c transmembrane protein 439 440
Rv2096c pafB proteasome accessory factor B 430 430 ctx cooccurence:430
Rv2467 pepN aminopeptidase PepN 414 352
Rv1202 dapE succinyl-diaminopimelate desuccinylase DapE 504 199 textmining:407

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 exp badge marks an experimentally-supported partner (measured interaction, experimental/database channel ≥400) as opposed to a purely predicted one — but note that the M. tuberculosis experimental interactome is dominated by a noisy bacterial-two-hybrid screen, so a strong measured link that contradicts the operon/localisation context is likely a false positive. 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

  • Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): hypothetical protein
  • Pfam (hmmscan --cut_ga): Peptidase_M28 PF04389.23 (E=9e-10), Peptidase_M20 PF01546.34 (E=5e-31), M20_dimer PF07687.20 (E=3e-14)
  • (auto-curated by rules from PGAP + Pfam + Foldseek; not hand-reviewed)

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 YP_177864.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Peptidase_M28 (PF04389.23), Peptidase_M20 (PF01546.34), M20_dimer (PF07687.20)
  • 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 COG0624
  • Curated reference: UniProt L7N684 (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)
  • Genome-wide structure: AlphaFold DB model (Jumper et al. 2021, doi:10.1038/s41586-021-03819-2; Varadi et al. 2024, doi:10.1093/nar/gkad1011) searched vs PDB with Foldseek (mean pLDDT 94.4)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 9 functional partner(s); context anchor ctaF
  • Essentiality: genome-wide transposon mutagenesis in H37Rv — DeJesus et al. 2017 (mBio, doi:10.1128/mBio.02133-16, CC BY)
  • Proteomics: integrated mass-spectrometry abundance from PaxDb 5.0 (Huang et al. 2023, doi:10.1016/j.mcpro.2023.100640), taxon 83332 — weighted average of 16 datasets, incl. Schubert et al. 2013 (doi:10.1016/j.chom.2013.04.008) and Albrethsen et al. 2013 (doi:10.1074/mcp.M112.018846)
  • Functional category: TubercuList scheme (Cole et al. 1998, doi:10.1038/31159), via Mycobrowser (Kapopoulou et al. 2011, doi:10.1016/j.tube.2010.09.006)
  • Orthologues: reciprocal best hits (DIAMOND, Buchfink et al. 2021, doi:10.1038/s41592-021-01101-x) against Mycobrowser release 5 reference proteomes
  • Genomic context / operon: H37Rv annotation; operon predicted by co-directional intergenic distance (Salgado et al. 2000, doi:10.1073/pnas.030539397)
  • Physico-chemical properties: ExPASy ProtParam method via Biopython (Gasteiger et al. 2005), computed from the MTBC0 sequence
  • Predicted localisation: DeepTMHMM (Hallgren et al. 2022, doi:10.1101/2022.04.08.487609) for transmembrane topology and signal peptide
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv2141c|
MTDETGASSDHSDDVAQVVSRLIRFDTTNSGEPGTTKGEAECARWVAEQLAEVGYQPEYVESGAPGRGNVFARLAGADSSRGALLIHGHLDVVPAEPAEWSVHPFSGAIEDGYVWGRGAVDMKDMVGMMIVVARHLRQAAIVPPRDLVFAFVADEEHGGKYGSHWLVDNRPDLFDGITEAIGEVGGFSLTVPRHDGGERRLYLIETAEKGIQWMRLTARGRAGHGSMVHDQNAVTAVCEAVARLGRHQFPLVCTDTVAQFLAVVGEETGLAFDLDSPDLAGTIDKLGPMARMLKAVLHDTANPTMLKAGYKANVVPATAEAVVDCRVLPGRRAAFEAEVDALIGPDVTREWVSDLPSYETTFDGDLVAAMNAAVLAVDPDGRTVPYMLSGGTDAKAFARLGIRCFGFSPLRLPPDLDFTSLFHGVDERVPIDGLRFGTEVLTHLLTHC