Rv2762c Family assigned · low auto-curated

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

Genomic neighbourhood (genome browser)

Open in full genome browser →
+ 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 qcrA (Rv2195) — requalified: hypothetical 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

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, pebble.rockefeller.edu).

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, 145 209 strains) pseudogene candidate

pN/pS 0.394 · purifying
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 10.12% of strains (14697) · clonal

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.
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: low-abundance, condition-specific, or MS-refractory proteins (e.g. small, highly hydrophobic, or repetitive PE/PPE families with few tryptic peptides) are systematically under-sampled.

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 (or not yet scanned).

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).

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: hsdS (type I restriction/modification system specificity determinant HsdS), high confidence from genomic context alone (score 947 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

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 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

  • 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 145 209 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
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002939|Rv2762c|
MSAATAAWDRRAAVVVGGVAEPGSAGPIAGADRKRLISRIQVRQLDSAAVAAKRRHLYYVRPLDGHPVARVDRKTDRAADSLPVAGVLGELDIPPVTVAEGLAGELASMASWLGLGGIAVSTRGDLAGELCAATKRTNG