Rv2762c Family assigned · low auto-curated

H37Rv Rv2762c · MTBC0 mtbc0_002939 · 139 aa · 3095052–3095471 MTBC0 (-) · RefSeq NP_217278.1

Genomic neighbourhood (genome browser)

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+ strand − strand ftsK (Rv2748c) — requalified: DNA translocase FtsK ftsK Rv2749 (Rv2749) — family_assigned: putative quinol monooxygenase Rv2750 (Rv2750) — family_assigned: Rv2750 family mycofactocin-dependent SDR oxidoreductase Rv2751 (Rv2751) — requalified: class I SAM-dependent methyltransferase Rv2751 rnj (Rv2752c) — requalified: ribonuclease J rnj dapA (Rv2753c) — requalified: 4-hydroxy-tetrahydrodipicolinate synthase dapA thyX (Rv2754c) — requalified: FAD-dependent thymidylate synthase hsdM (Rv2756c) — requalified: class I SAM-dependent DNA methyltransferase hsdM vapC21 (Rv2757c) — requalified: type II toxin-antitoxin system toxin ribonuclease C21 vapB21 (Rv2758c) — family_assigned: type II toxin-antitoxin system VapB family antitoxin vapC42 (Rv2759c) — family_assigned: type II toxin-antitoxin system VapC family toxin vapB42 (Rv2760c) — family_assigned: type II toxin-antitoxin system VapB family antitoxin hsdS (Rv2761c) — family_assigned: restriction endonuclease subunit S hsdS Rv2762c (Rv2762c) — family_assigned: winged helix-turn-helix domain-containing protein dfrA (Rv2763c) — requalified: dihydrofolate reductase Rv2765 (Rv2765) — family_assigned: dienelactone hydrolase family protein Rv2767c (Rv2767c) — family_assigned: hypothetical protein Rv2771c (Rv2771c) — family_assigned: flavodoxin family protein Rv2772c (Rv2772c) — family_assigned: hypothetical protein dapB (Rv2773c) — requalified: 4-hydroxy-tetrahydrodipicolinate reductase Rv2774c (Rv2774c) — dark: hypothetical protein Rv2777c (Rv2777c) — requalified: metal-dependent hydrolase 3 084 kb 3 088 kb 3 092 kb 3 096 kb 3 100 kb 3 104 kb

This gene (outlined) in its genomic context; arrows are neighbouring genes coloured by verdict. Click any gene to navigate. Pan and zoom in the full browser.

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationwinged helix-turn-helix domain-containing protein
Revised (this work)Winged helix-turn-helix domain-containing protein.
Functional category (TubercuList)conserved hypotheticals

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

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
Insights from the protein-protein interaction network analysis of Mycobacterium tuberculosis toxin-antitoxin systems. doi:10.6026/97320630013380 2017
1 record returned by the alias sweep

Searched as: Rv2762c, Mb2783c, MMAR_1958, MSMEG_2679 — each in conjunction with a mycobacterial context term. Swept 2026-09-07.

PublicationJournalYear
Insights from the protein-protein interaction network analysis of Mycobacterium tuberculosis toxin-antitoxin systems. doi:10.6026/97320630013380 Bioinformation 2017

Title+abstract index only: a paper that names this gene solely in its body text, a figure legend or a supplement is invisible here. That is why this list sits beside the curated layer rather than replacing it - Rv0007's characterisation, found by a full-text sweep, returns zero in this one. Absence from this list is not absence from the literature. Source: PubMed E-utilities sweep (esearch + esummary), every alias of the gene searched in conjunction with a mycobacterial context term; ambiguous common-word aliases excluded. phase198, 2026-09-06.

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.

Intrinsic disorder (sequence + structure) partially disordered

Predicted disorder20% of residues (metapredict) · mean AlphaFold pLDDT 57.9
Disordered regions1 IDR(s), longest 28 aa [0-28]

carries a substantial disordered region (28/139 residues); disorder is a property, not a function

A property (biophysics), not a function. No LLPS/condensate claim is made from disorder alone. Verdict unchanged. Source: metapredict v3 (Emenecker/Holehouse) per-residue disorder + AlphaFold mean pLDDT (annotation_mtbc P16.13).

Genomic-neighbour overlap (structural caveat) co-directional · 1 % of gene

NeighbourhsdS (Rv2761c, - strand)
Overlap4 bp, 1 % of this gene's length

co-directional overlap: ordinary (e.g. shared stop/start codons in an operon), not the Rv2438A-type artefact P20.1, derived from GFF3 gene coordinates, 2026-08-03.

CRISPRi vulnerability

Vulnerability index 0.55 (95% CI -0.57 to 1.84). 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, supplementary Table S2 'mmc3.xlsx', bulk import via Europe PMC -- supersedes the per-gene pebble.rockefeller.edu scrape of phase46_crispri_vulnerability.py).

Caveat on this estimate. Bosch et al. flag this gene's vulnerability estimate as NOT certain, and here that call has a mechanical cause visible in the library itself: every guide targeting this gene is >=21 nt (str_span=0.077 on a 0-1 scale, near the genome floor), and guide repression strength saturates from 21 nt on -- so the library never sampled a partial knockdown for this gene, only the near-maximal repression plateau. The dose-response fit (and this VI) is therefore essentially unconstrained by data, not merely uncertain -- a limitation of the CRISPRi library design for the non-essential class (Bosch et al. 2021), not a defect in this specific measurement. n_guides=4 is descriptive only and does not predict this. Do not cite this VI as a standalone vulnerability claim.

Legacy record & comparison (Mycobrowser)

Mycobrowser functionFunction unknown

The legacy Mycobrowser record is shown for verification. Mycobrowser is no longer maintained; its EC numbers predate recent nomenclature revisions, so a class change usually reflects re-numbering, not a conflict.

Orthologues (reciprocal best hits across mycobacteria)

M. bovis Mb2783c · 98.9% identity
M. marinum MMAR_1958 · 59.6% identity
M. smegmatis MSMEG_2679 · 49.4% 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 I6X5B0 TrEMBL · unreviewed · Predicted
UniProt nameWinged helix-turn-helix domain-containing protein

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
eggNOG descriptionWinged helix DNA-binding domain
Orthologous groupCOG3214
KEGG orthology K09927

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, 142 601 strains, snapshot of 2026-09-29) pseudogene candidate

pN/pS 0.394 · quasi-invariant (2 sites), pN/pS underpowered
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 0 missense, 1 nonsense, 2 frameshift
Disruption 3 distinct premature-stop/frameshift site(s); most common in 9.45% of strains (13476) · clonal
Which clade carries which site (attribution) site unique fixé — Bovis, Caprae_La2, La4; union over all sites: 13 910 strains (the count above is a maximum over sites, not a union).
  • NC_000962.3:3072926:G:A · nonsense · 13 476 strains — fixed in 334 sub-clades of Bovis, Caprae_La2, La4, totalling 13 080 strains — 97.0% of the 13 490 strains in the lineages named (largest: Bovis.2.2.1.2.2.2.1.1.1.1.2.9 1760/1763, Bovis.2.2.1.2.2.2.1.1.1.1.1.2.2.2.2.1.3 479/480, Bovis.2.2.1.2.2.2.1.1.1.1.3.3 346/346, Bovis.2.2.1.2.2.2.1.2.3.2 313/315, Bovis.2.1.2.2.2.1.3.2.2.2 249/249, Bovis.2.2.1.2.2.2.1.1.1.1.1.1 243/244, …)
  • NC_000962.3:3072704:T:TC · frameshift · 249 strains — not fixed in any clade
  • NC_000962.3:3072704:TC:T · frameshift · 185 strains — not fixed in any clade
Which clade carries which disrupting site — the question the count above never asked. `disrupt_strains` is a MAXIMUM over sites, not a union: two sites carried by two disjoint clades do not add up there. `disrupt_mode` is derived from the NUMBER of sites alone (convergent at 4 or more), so it says nothing about who carries them. Read this field instead for any evolutionary claim, and mind the distinction it enforces: several clades at the SAME site is shared ancestry, not convergence — convergence requires DIFFERENT sites in DIFFERENT clades. SECOND CORRECTION (P44.8, same day): a clade name listed here is the ROOT of the fine clade that fixes the site, not the whole lineage. Across the 789 fixed sites of this atlas, the fixing sub-clades cover a median of 9.2% of the lineage named, and under 10% for half of them — so read the sub-clade sizes given here, never the lineage name alone.

Read the disruption percentage against its ceiling, not against 100%. The strain collection is deeply imbalanced by clade, so a loss fixed in an entire lineage still shows a small overall fraction: a gene disrupted in every L6 strain caps at 0.96% of the collection, in every M. caprae strain at 0.20%, in every M. microti strain at 0.02%. Of the 705 clades in this collection, 689 have a ceiling below 1%. A figure of "0.15% of strains" is therefore uninterpretable on its own — it can be noise or a complete, lineage-defining loss. Use the clade attribution row above, which gives the sub-clade sizes, and never read the percentage alone.

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) Corynebacteriales

Genus-wide presence (~53 non-MTBC Mycobacterium) present in 46/53 (87%) · mean identity 60.4% · 3/4 closest MTBAP relatives
conserved across the genus (present in 46/53 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 4/13 non-Mycobacterium reference genomes (down to Corynebacteriales) · mean identity 48.4%
detected across the order Corynebacteriales (Corynebacterium/Nocardia/Rhodococcus/…) but not in more distant Actinomycetia — a Corynebacteriales-level 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) 5 in the ORF — 0 in the essential state, 0 growth-defect, 5 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 36.4. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction.
All 5 sites lie in this ORF alone (no overlapping CDS shares any), so the call is attributable to this gene.
CaveatRead with some caution: only 5 TA (Himar1) sites in the whole ORF (atlas median 13). The DeJesus 2017 call rests on fewer independent observations than for a longer gene. If this gene overlaps a neighbour (see Genomic-neighbour overlap section below), some of these 5 sites may fall inside the neighbour's ORF rather than its own, leaving even fewer truly informative sites than the raw count suggests. (P20.3)

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) not detected

Not detected in the mass-spectrometry datasets integrated by PaxDb. This is not evidence of absence, and this atlas can say which bias dominates, because it measured it on its own 482 undetected proteins. Size is the main factor: undetected proteins have a median length of 145 aa against 295 aa for detected ones, and 25.3 % of them are shorter than 100 aa against 6.0 %. Predicted localisation matters far less than usually assumed: detection rates are 89.3 % for globular, 84.9 % for transmembrane, 88.0 % for lipoproteins and 77.8 % for signal-peptide proteins — so a short protein is under-sampled whatever its predicted compartment, and hydrophobicity alone is a weak excuse. Condition-specific expression and few tryptic peptides (PE/PPE repeats) add to this.

Predicted localisation (DeepTMHMM + lipobox) no export signal, no TM helix

Predictionno signal peptide, no TM helix (DeepTMHMM class GLOB)
DeepTMHMM classGLOB

A verified absence of signals, which is not a compartment. No Sec/Tat signal peptide, no transmembrane helix and no lipobox were found on this sequence. The predictor reports topology and export signals; it does not measure where the protein ends up, so this page draws no cytoplasmic conclusion from it. In M. tuberculosis that reservation is not theoretical: the 12 Esx paralogues of this atlas — EsxA/ESAT-6 and EsxB/CFP-10 among them, the best-established secreted proteins of the species — carry this very call, because substrates of the type VII (ESX) secretion system leave no recognisable signal. « Secreted » and « no signal peptide » are true together here.

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)

Length139 aa
Molecular weight14.3 kDa
Theoretical pI9.73
GRAVY0.048 (hydrophobic)
Aliphatic index98.4
Aromaticity0.029
Instability index37.2 (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)

No Pfam-A domain above the gathering threshold (hmmscan --cut_ga scan completed).

3D structure (interactive — Mol*/pdbe-molstar)

No experimental structure is deposited for this gene: showing the AlphaFold DB predicted model (mean pLDDT 57.9, low), coloured by per-residue confidence (dark blue = very high, orange/red = low — treat low-confidence regions as unreliable, especially termini and loops). Drag to rotate, scroll to zoom.

Genomic context (neighbours & predicted operon) operon of 6

Upstream (5' on genome)hsdS (- strand, -4 bp gap)
Downstream (3' on genome)dfrA (- strand, 73 bp gap)
Predicted operon vapC21 · vapB21 · vapC42 · vapB42 · hsdS · Rv2762c

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).

Published operon evidence (two independent sources)

Roback 2007 (logistic regression: distance + expression correlation, 474 microarrays) operon of 2: hsdS · Rv2762c — disagrees with the distance heuristic above
REMap 2016 (RNA-seq coverage continuity, CDC1551, tag MT2832) exponential phase: operon of 8, Rv2755c · Rv2756c · Rv2757c · Rv2758c · Rv2759c · Rv2760c · Rv2761c · Rv2762c (coverage 8.6)
not expressed (stationary phase) — disagrees with the distance heuristic above

Two independent published operon maps, cited alongside the distance heuristic above: an association corroborating or contradicting the heuristic, never proof of shared function. REMap's RNA-seq coverage continuity is the most direct of the three signals; Roback's logistic regression and the intergenic-distance heuristic are statistical proxies.

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

Explore full network →

Node colour = verdict, dashed = still uncharacterised; 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: hsdS (type I restriction/modification system specificity determinant HsdS), high confidence (score 947, all STRING channels except text-mining; the partner is chosen on its genomic-context evidence).

All 13 partner(s) at medium confidence are shown. None rests on an interaction measured in M. tuberculosis itself.

PartnerProductScoreNo text-miningChannels (≥400)
Rv2761c hsdS type I restriction/modification system specificity determinant HsdS 947 947 ctx neighborhood:800 coexpression:746
Rv2763c dfrA dihydrofolate reductase 937 827 ctx neighborhood:791 textmining:651
Rv2759c vapC42 ribonuclease VapC42 802 803 ctx neighborhood:800
Rv2760c vapB42 antitoxin VapB42 802 803 ctx neighborhood:800
Rv2756c hsdM type I restriction/modification system DNA methylase HsdM 745 745 ctx neighborhood:741
Rv2764c thyA thymidylate synthase ThyA 874 733 ctx neighborhood:730 textmining:548
Rv2757c vapC21 ribonuclease VapC21 960 711 ctx neighborhood:707 textmining:870
Rv2758c vapB21 antitoxin VapB21 710 710 ctx neighborhood:707
Rv2765 hydrolase 673 673 ctx neighborhood:673
Rv2754c thyX thymidylate synthase ThyX 755 669 ctx neighborhood:667
Rv2753c dapA 4-hydroxy-tetrahydrodipicolinate synthase 755 655 ctx neighborhood:643
Rv2752c rnj ribonuclease J 788 640 ctx neighborhood:635 textmining:436
Rv2755c hsdS.1 Rv2755c, (MTV002.20c), len: 91 aa. Possible hsdS.1,fragment of type I restriction/modification system specificity determinant (S protein), s 560 560 ctx neighborhood:557

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.

Where the experimental evidence comes from, and why it matters here. STRING's experimental channel fuses interactions measured in M. tuberculosis with interactions measured in another organism and transferred to this pair by orthology. The two are not equivalent for this atlas, whose standing rule is that better studied elsewhere is not a function established in M. tuberculosis. Measured on the served network: of the 38 229 partner pairs shown across the atlas, 13 483 partner rows carry a non-zero experimental channel, and only 106 pairs rest on an interaction measured in M. tuberculosis itself — 0.3 % of the network. Those 106 are long-established complexes (ESX-1/ESAT-6, RNA polymerase with CarD and RbpA, the Pup–Mpa proteasome, gyrase, Emb, GarA with PknB and PknG, the Rel modules); no still-uncharacterised gene is among them. The reason is not a gap in this atlas but in the literature: there is almost no experimental interactome of this bacterium, IntAct holding 134 curated protein pairs for a ~4 000-gene proteome. A exp (transferred) badge is therefore a lead, never a measurement, and an absence of badge is not evidence that the pair does not interact.

Evidence

  • Legacy H37Rv annotation: hypothetical protein
  • MTBC0 PGAP product: winged helix-turn-helix domain-containing protein
  • (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 NP_217278.1)
  • 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 COG3214
  • Curated reference: UniProt I6X5B0 (TrEMBL, unreviewed; Predicted)
  • Intra-MTBC selection: pN/pS and disruption from SPDI variants of 142 601 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 — 13 functional partner(s); context anchor hsdS
  • Essentiality: genome-wide transposon mutagenesis in H37Rv — DeJesus et al. 2017 (mBio, doi:10.1128/mBio.02133-16, CC BY)
  • 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

>mtbc0_002939|Rv2762c|
MSAATAAWDRRAAVVVGGVAEPGSAGPIAGADRKRLISRIQVRQLDSAAVAAKRRHLYYVRPLDGHPVARVDRKTDRAADSLPVAGVLGELDIPPVTVAEGLAGELASMASWLGLGGIAVSTRGDLAGELCAATKRTNG