Rv3364c Resolved · high auto-curated

H37Rv Rv3364c · MTBC0 mtbc0_003579 · 130 aa · 3801190–3801582 MTBC0 (-) · RefSeq NP_217881.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationserine protease inhibitor
Revised (this work)Serine protease inhibitor. Pfam: Robl_LC7 (PF03259.24).
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) 3 publications

Found under: H37Rv (3).

3 TB publications mention this gene. 3 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
Interaction of Mycobacteria With Host Cell Inflammasomes. doi:10.3389/fimmu.2022.791136 2022
Discovery of Mycobacterium tuberculosis Rv3364c-Derived Small Molecules as Potential Therapeutic Agents to Target SNX9 for Sepsis. doi:10.1021/acs.jmedchem.1c01551 2022
Inhibition of the Plasma-Membrane-Associated Serine Protease Cathepsin G by Mycobacterium tuberculosis Rv3364c Suppresses Caspase-1 and Pyroptosis in Macrophages. doi:10.3389/fmicb.2011.00281 2011

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.

Genomic-neighbour overlap (structural caveat) co-directional · 6 % of gene

NeighbourRv3363c (Rv3363c, - strand)
Overlap23 bp, 6 % 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 1.20 (95% CI -0.51 to 3.94). 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) ahead of Mycobrowser

Mycobrowser functionFunction unknown

Mycobrowser classes this locus among conserved hypotheticals; the atlas now assigns a functional handle (curated function (UniProt), requalified function). Mycobrowser is no longer maintained, so its EC numbers predate recent nomenclature revisions (e.g. the 2018 EC 7 "translocase" class) — most EC differences are re-numberings of the same enzyme, not conflicts.

Orthologues (reciprocal best hits across mycobacteria)

M. bovis Mb3399c · 100.0% identity
M. marinum MMAR_1166 · 87.7% identity
M. smegmatis MSMEG_1638 · 82.6% identity
M. orygis RJtmp_003467 · 100.0% 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 O50393 SwissProt · reviewed · Evidence at protein level
UniProt nameSerine protease inhibitor Rv3364c
Curated functionEffector protein that binds to the host serine protease cathepsin G on the macrophage cell membrane, inhibiting its enzymatic activity and the downstream activation of caspase-1-dependent apoptosis. Thus prevents macrophage pyroptosis and helps M.tuberculosis survival within host cells.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
eggNOG descriptionPFAM Roadblock LC7
Orthologous groupCOG2018
KEGG orthology K07131

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 0.723 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 2 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

Genus-wide presence (~53 non-MTBC Mycobacterium) present in 51/53 (96%) · mean identity 86.1% · 4/4 closest MTBAP relatives
conserved across the genus (present in 51/53 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 3/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 67.1%
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) 5 in the ORF — 0 in the essential state, 0 growth-defect, 5 non-essential, 0 growth-advantage. Saturation 0.800, mean read count 108.5. 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) detected

MS detectiondetected in 10 of 16 independent MS datasets
Integrated abundance82.7 ppm · rank 1432/3519 (59.3th 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.

Physico-chemical properties (computed, ProtParam)

Length130 aa
Molecular weight13.4 kDa
Theoretical pI4.97
GRAVY0.373 (hydrophobic)
Aliphatic index111.1
Aromaticity0.038
Instability index35.7 (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
Robl_LC7PF03259.24 2.3e-2410–101 Roadblock/LC7 domain

Experimental structures (Protein Data Bank) 1 solved

PDBMethodResolutionCoverage
9hef X-ray diffraction 1.83 Å 99%

Experimentally solved structures mapped from the UniProt accession via PDBe/SIFTS (1 total; up to 8 shown, ranked by sequence coverage then resolution). An experimental structure is direct proof of the folded product and the strongest structural evidence — superseding the predicted ESMFold/AlphaFold models below for any covered region.

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 91.2

PDB hitprobTM-scoreE-valueDescription
3kye-assembly2_C 1.00 0.93 1.3e-10 sig 3kye-assembly2_C Crystal Structure of Roadblock/LC7 Domain from Streptomyces avermitilis
3leq-assembly1_A 1.00 0.92 2.2e-09 sig 3leq-assembly1_A The Crystal Structure of the Roadblock/LC7 domain from Streptomyces avermitillis to 1.85A
7f8m-assembly3_F 1.00 0.89 8.0e-09 sig 7f8m-assembly3_F Roadblock from Thorarchaeota SMTZ1-45
6hjm-assembly2_E 1.00 0.89 6.4e-08 sig 6hjm-assembly2_E Myxococcus xanthus MglB
6hjm-assembly9_P 1.00 0.90 1.0e-07 sig 6hjm-assembly9_P Myxococcus xanthus MglB

Foldseek search of the AlphaFold DB model (mean pLDDT 91.2, 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 5

Upstream (5' on genome)Rv3363c (- strand, -23 bp gap)
Downstream (3' on genome)Rv3365c (- strand, -4 bp gap)
Predicted operon Rv3361c · Rv3362c · Rv3363c · Rv3364c · Rv3365c

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: Rv3362c (ATP/GTP-binding protein), high confidence from genomic context alone (score 1000 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv3362c exp ATP/GTP-binding protein 999 1000 ctx neighborhood:882 cooccurence:774 coexpression:807 experimental:917 textmining:838
Rv3363c hyp hypothetical protein 997 984 ctx neighborhood:882 cooccurence:774 coexpression:458 textmining:870
Rv3365c hyp hypothetical protein 994 973 ctx neighborhood:882 cooccurence:769 textmining:810
Rv3361c mfpA hyp hypothetical protein 984 887 ctx neighborhood:882 textmining:870
Rv3366 spoU tRNA/rRNA methylase SpoU 493 492 ctx neighborhood:486
Rv0585c integral membrane protein 452 453 ctx cooccurence:451
Rv0923c hyp hypothetical protein 429 429 ctx cooccurence:423
Rv0047c hyp hypothetical protein 422 422 ctx cooccurence:421
Rv2068c blaC beta-lactamase 706 195 textmining:651
Rv3151 nuoG NADH-quinone oxidoreductase subunit G 582 179 textmining:513
Rv3671c marP serine protease 640 83 textmining:624
Rv3654c hyp hypothetical protein 659 45 textmining:658
Rv0198c zmp1 zinc metalloprotease 521 44 textmining:520
Rv3354 hyp hypothetical protein 803 41 textmining:803

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: serine protease inhibitor
  • Pfam (hmmscan --cut_ga): Robl_LC7 PF03259.24 (E=2e-24)
  • (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_217881.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Robl_LC7 (PF03259.24)
  • 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 COG2018
  • Curated reference: UniProt O50393 (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)
  • 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 91.2)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 14 functional partner(s); context anchor Rv3362c
  • 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
  • Experimental structures: PDBe/SIFTS UniProt→PDB mapping (Dana et al. 2019, doi:10.1093/nar/gky1114)
  • 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_003579|Rv3364c|
MKARLPDSPLDWLVSKFAREVPGVAHALLVSVDGLPVAASEHLPRERADQLAAVTSGLASLAGGAAQLFDGGQVLQSVVEMQNGYLLLMQVGDGSALAALAATGCDIGQIGYEMAILVERVGGVVQSCRR