menJ Resolved · high auto-curated

H37Rv Rv0561c · MTBC0 mtbc0_000590 · 408 aa · 655080–656306 MTBC0 (-) · RefSeq NP_215075.1

Genomic neighbourhood (genome browser)

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+ strand − strand vapC3 (Rv0549c) — family_assigned: type II toxin-antitoxin system VapC family toxin vapB3 (Rv0550c) — family_assigned: type II toxin-antitoxin system CcdA family antitoxin fadD8 (Rv0551c) — requalified: fatty-acid--CoA ligase FadD8 fadD8 Rv0552 (Rv0552) — requalified: amidohydrolase Rv0552 menC (Rv0553) — requalified: o-succinylbenzoate synthase menC bpoC (Rv0554) — family_assigned: alpha/beta hydrolase menD (Rv0555) — requalified: 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxyli menD Rv0556 (Rv0556) — family_assigned: DUF3592 domain-containing protein Rv0559c (Rv0559c) — family_assigned: DUF732 domain-containing protein menJ (Rv0561c) — requalified: menaquinone reductase menJ grcC1 (Rv0562) — requalified: polyprenyl-diphosphate synthase GrcC grcC1 htpX (Rv0563) — requalified: zinc metalloprotease HtpX htpX gpdA1 (Rv0564c) — requalified: NAD(P)H-dependent glycerol-3-phosphate dehydrogenase gpdA1 Rv0565c (Rv0565c) — requalified: NAD(P)/FAD-dependent oxidoreductase Rv0565c Rv0566c (Rv0566c) — family_assigned: YajQ family cyclic di-GMP-binding protein Rv0567 (Rv0567) — requalified: methyltransferase Rv0567 cyp135B1 (Rv0568) — requalified: cytochrome P450 cyp135B1 Rv0569 (Rv0569) — family_assigned: DUF1918 domain-containing protein nrdZ (Rv0570) — requalified: adenosylcobalamin-dependent ribonucleoside-diphosphate reduc nrdZ Rv0571c (Rv0571c) — family_assigned: phosphoribosyltransferase family protein 644 kb 648 kb 652 kb 656 kb 660 kb 664 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)oxidoreductase
MTBC0 PGAP re-annotationmenaquinone reductase
Revised (this work)Menaquinone reductase. Pfam: FAD_binding_3 (PF01494.26), Pyr_redox_2 (PF07992.21), Lycopene_cycl (PF05834.19), FAD_oxidored (PF12831.14), FAD_binding_2 (PF00890.31), GIDA (PF01134.29), NAD_binding_8 (PF13450.13).
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.

In the literature (TB corpus sweep) 5 publications

5 TB publications mention this gene. 5 publication(s) discuss this gene (4 in a M. tuberculosis context, 2 in other mycobacteria — M. smegmatis (2)).

PublicationDate
Mycobacterium tuberculosis Survival in J774A.1 Cells Is Dependent on MenJ Moonlighting Activity, Not Its Enzymatic Activity. doi:10.1021/acsinfecdis.0c00312 2020
Investigating Substrate Analogues for Mycobacterial MenJ: Truncated and Partially Saturated Menaquinones. doi:10.1021/acs.biochem.9b00007 2019
Demethylmenaquinone Methyl Transferase Is a Membrane Domain-Associated Protein Essential for Menaquinone Homeostasis in Mycobacterium smegmatis. doi:10.3389/fmicb.2018.03145 2018
Mycobacterial MenJ: An Oxidoreductase Involved in Menaquinone Biosynthesis. doi:10.1021/acschembio.8b00402 2018
Partial Saturation of Menaquinone in Mycobacterium tuberculosis: Function and Essentiality of a Novel Reductase, MenJ. doi:10.1021/acscentsci.5b00212 2015

This layer CITES the literature and adds context; it does not change the verdict or the function stated elsewhere in this fiche. This distinguishes a gene that is dark because nobody has looked from one that is dark despite having been studied. Source: PubMed (whole): H37Rv locus tag + GENE NAME + ortholog identifiers (Mb…, MMAR_…, MSMEG_…, ML…, MAB_…), under a mycobacterial context filter; hits verified against the abstract text. Species-context counts distinguish M. tuberculosis literature from literature on other mycobacteria. phase76/phase77, 2026-07-13.

CRISPRi vulnerability

Vulnerability index 0.72 (95% CI -0.75 to 3.13). 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; probably involved in cellular metabolism.
Mycobrowser EC 1.-.-.- · superseded EC numbering; the atlas uses the current class (1.3.99.38)

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 Mb0576c · 100.0% identity
M. leprae ML2276c · 84.3% identity
M. marinum MMAR_0910 · 87.3% identity
M. smegmatis MSMEG_1132 · 74.1% identity
M. orygis RJtmp_000589 · 100.0% identity
M. abscessus MAB_3929 · 67.5% 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 P9WNY9 SwissProt · reviewed · Evidence at protein level
UniProt nameMenaquinone reductase
EC (curated) EC 1.3.99.38
Curated functionCatalyzes the reduction of a single double bond in the isoprenoid tail of menaquinone (MK-9) in M.tuberculosis, likely the beta-isoprene unit, forming the predominant form of menaquinone found in mycobacteria, MK-9(II-H2). Is required for M.tuberculosis survival in host macrophages.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category C Energy production and conversion
Preferred namemenJ
eggNOG descriptiongeranylgeranyl reductase
Orthologous groupCOG0644
EC number EC 1.3.99.38
KEGG orthology K21401
Gene Ontology (31) GO:0003674, GO:0003824, GO:0005575, GO:0005618, GO:0005623, GO:0006732, GO:0008150, GO:0008152, GO:0009058, GO:0009108, GO:0009233, GO:0009234 +19 more

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 0.285 · purifying
Polymorphic sites (≥ 0.1% of strains) 4 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.

Outgroup conservation (beyond the MTBC) Actinomycetia

M. canettii dN/dS (deep-divergence selection) 0.571 (low power) · 5 consensus substitution(s)
low power (5 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 84.1% · 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 9/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 50.9%
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) 18 in the ORF — 0 in the essential state, 0 growth-defect, 18 non-essential, 0 growth-advantage. Saturation 0.889, mean read count 41.25. 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.

Mutant phenotypes (conditional Tn-seq, MtbTnDB) in-vivo phenotype

Conditionlog2FCqEffect
fitness in mouse infection (in vivo) -4.620.0 required
fitness in mouse infection, day 45 (in vivo) -4.440.0 required
fitness in mouse infection (in vivo) -4.320.0075 required
fitness in mouse infection (in vivo) -4.300.0089 required
altered fitness under 6 weeks hypoxia (stress) -3.990.0 required
fitness in mouse infection (in vivo) -3.530.02 required
altered fitness under nitrosative (NO) stress (stress) -3.500.032 required
fitness in mouse infection (in vivo) -3.250.019 required
fitness in mouse infection (in vivo) -3.180.011 required
fitness in mouse infection (in vivo) -3.020.0 required
fitness in mouse infection (in vivo) -2.600.019 required
fitness in mouse infection (in vivo) -2.430.034 required

Conditional fitness of transposon-disruption mutants across 14 significant condition(s) (|log2FC|≥1, q≤0.05), from the standardized MtbTnDB compendium. A negative log2FC means the mutant is depleted — the gene contributes to fitness in that condition. An in-vivo defect for a "hypothetical" is strong evidence it matters for infection, even without a known molecular function. Disruption (Tn insertion), not a clean deletion; genetic-interaction screens excluded.

Proteomics (mass spectrometry) detected

MS detectiondetected in 10 of 16 independent MS datasets
Integrated abundance8.96 ppm · rank 2727/3519 (22.5th 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)

Length408 aa
Molecular weight43.9 kDa
Theoretical pI9.04
GRAVY-0.078 (hydrophilic)
Aliphatic index92.5
Aromaticity0.071
Instability index37.8 (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
FAD_binding_3PF01494.26 2.7e-157–181 FAD binding domain
Pyr_redox_2PF07992.21 4.0e-108–162 Pyridine nucleotide-disulphide oxidoreductase
Lycopene_cyclPF05834.19 2.2e-088–300 Lycopene cyclase protein
FAD_oxidoredPF12831.14 3.2e-078–144 FAD dependent oxidoreductase
FAD_binding_2PF00890.31 4.2e-058–37 FAD binding domain
GIDAPF01134.29 8.3e-058–36 Glucose inhibited division protein A
NAD_binding_8PF13450.13 4.4e-0511–39 NAD(P)-binding Rossmann-like domain

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 92.5

PDB hitprobTM-scoreE-valueDescription
3oz2-assembly1_A 1.00 0.77 4.2e-26 sig 3oz2-assembly1_A Crystal structure of a geranylgeranyl bacteriochlorophyll reductase-like (Ta0516) from Thermoplasma acidophilum at 1.60 A resolution
5bva-assembly1_A 1.00 0.74 1.2e-24 sig 5bva-assembly1_A Structure of flavin-dependent brominase Bmp2
5bul-assembly1_A 1.00 0.73 3.5e-24 sig 5bul-assembly1_A Structure of flavin-dependent brominase Bmp2 triple mutant Y302S F306V A345W
6sw2-assembly1_A 1.00 0.72 6.3e-21 sig 6sw2-assembly1_A Crystal Structure of P. aeruginosa PqsL in complex with 2-aminobenzoylacetate
6sw1-assembly1_A 1.00 0.69 2.2e-21 sig 6sw1-assembly1_A Crystal Structure of P. aeruginosa PqsL: R41Y, I43R, G45R, C105G mutant

Foldseek search of the AlphaFold DB model (mean pLDDT 92.5, 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 3

Upstream (5' on genome)Rv0560c (- strand, 24 bp gap)
Downstream (3' on genome)grcC1 (+ strand, 15 bp gap)
Predicted operon Rv0559c · Rv0560c · Rv0561c

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: Rv0560c (benzoquinone methyltransferase), high confidence from genomic context alone (score 745 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3029c fixA exp electron transfer flavoprotein subunit beta 779 750 experimental:652
Rv0560c benzoquinone methyltransferase 901 745 ctx neighborhood:707 textmining:630
Rv0562 grcC1 polyprenyl-diphosphate synthase GrcC 751 736 ctx neighborhood:620
Rv0563 htpX protease HtpX 715 715 ctx neighborhood:714
Rv0559c hyp hypothetical protein 849 684 ctx neighborhood:684 textmining:543
Rv3028c fixB exp electron transfer flavoprotein subunit alpha 632 583 experimental:446
Rv2062c cobN cobalamin biosynthesis protein CobN 516 452 coexpression:434
Rv3806c ubiA decaprenyl-phosphate phosphoribosyltransferase 501 434
Rv2850c magnesium chelatase 584 427 coexpression:408
Rv0989c grcC2 polyprenyl-diphosphate synthase GrcC 446 413
Rv0958 magnesium chelatase 412 357
Rv3397c phyA phytoene synthase 417 339
Rv2110c prcB proteasome subunit beta 512 241
Rv2109c prcA proteasome subunit alpha 589 239 textmining:483
Rv0534c menA 1,4-dihydroxy-2-naphthoate octaprenyltransferase 708 186 textmining:656

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: oxidoreductase
  • MTBC0 PGAP product: menaquinone reductase
  • Pfam (hmmscan --cut_ga): FAD_binding_3 PF01494.26 (E=3e-15), Pyr_redox_2 PF07992.21 (E=4e-10), Lycopene_cycl PF05834.19 (E=2e-08), FAD_oxidored PF12831.14 (E=3e-07), FAD_binding_2 PF00890.31 (E=4e-05), GIDA PF01134.29 (E=8e-05), NAD_binding_8 PF13450.13 (E=4e-05)
  • (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_215075.1)
  • Domains: Pfam-A via hmmscan --cut_ga — FAD_binding_3 (PF01494.26), Pyr_redox_2 (PF07992.21), Lycopene_cycl (PF05834.19), FAD_oxidored (PF12831.14), FAD_binding_2 (PF00890.31), GIDA (PF01134.29), NAD_binding_8 (PF13450.13)
  • 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 COG0644
  • Curated reference: UniProt P9WNY9 (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 92.5)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 23 functional partner(s); context anchor Rv0560c
  • 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)
  • Mutant phenotypes: standardized Tn-seq compendium MtbTnDB (Jinich et al. 2025, doi:10.1111/mmi.15370), aggregating many primary Tn-seq studies across conditions
  • 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_000590|Rv0561c|menJ
MSVDDSADVVVVGAGPAGSAAAAWAARAGRDVLVIDTATFPRDKPCGDGLTPRAVAELHQLGLGKWLADHIRHRGLRMSGFGGEVEVDWPGPSFPSYGSAVARLELDDRIRKVAEDTGARMLLGAKAVAVHHDSSRRVVSLTLADGTEVGCRQLIVADGARSPLGRKLGRRWHRETVYGVAVRGYLSTAYSDDPWLTSHLELRSPDGAVLPGYGWIFPLGNGEVNIGVGALSTSRRPADLALRPLISYYTDLRRDEWGFTGQPRAVSSALLPMGGAVSGVAGSNWMLIGDAAACVNPLNGEGIDYGLETGRLAAELLDSRDLARLWPSLLADRYGRGFSVARRLALLLTFPRFLPTTGPITMRSTALMNIAVRVMSNLVTDDDRDWVARVWRGGGQLSRLVDRRPPFS