Rv3594 Resolved · high auto-curated

H37Rv Rv3594 · MTBC0 mtbc0_003813 · 275 aa · 4059534–4060361 MTBC0 (+) · RefSeq NP_218111.1

Genomic neighbourhood (genome browser)

Open in full genome browser →
+ strand − strand ispF (Rv3581c) — requalified: 2-C-methyl-D-erythritol 2%2C4-cyclodiphosphate synthase ispD (Rv3582c) — requalified: 2-C-methyl-D-erythritol 4-phosphate cytidylyltransferase carD (Rv3583c) — requalified: RNA polymerase-binding transcription factor CarD lpqE (Rv3584) — family_assigned: hypothetical protein radA (Rv3585) — requalified: DNA repair protein RadA radA disA (Rv3586) — requalified: DNA integrity scanning diadenylate cyclase DisA disA Rv3587c (Rv3587c) — family_assigned: hypothetical protein canB (Rv3588c) — requalified: beta-carbonic anhydrase CanB mutY (Rv3589) — requalified: A/G-specific adenine glycosylase mutY Rv3591c (Rv3591c) — family_assigned: alpha/beta hydrolase mhuD (Rv3592) — requalified: mycobilin-forming heme oxygenase MhuD lpqF (Rv3593) — requalified: serine hydrolase lpqF Rv3594 (Rv3594) — requalified: N-acetylmuramoyl-L-alanine amidase Rv3594 lsr2 (Rv3597c) — requalified: histone-like nucleoid-structuring protein Lsr2 lysS (Rv3598c) — requalified: lysine--tRNA ligase lysS Rv3600c (Rv3600c) — requalified: type III pantothenate kinase panD (Rv3601c) — requalified: aspartate 1-decarboxylase panC (Rv3602c) — requalified: pantoate--beta-alanine ligase panC Rv3603c (Rv3603c) — family_assigned: Rossmann-like and DUF2520 domain-containing protein Rv3603c Rv3604c (Rv3604c) — dark: DUF6779 domain-containing protein Rv3604c Rv3605c (Rv3605c) — family_assigned: DUF3180 domain-containing protein folK (Rv3606c) — requalified: 2-amino-4-hydroxy-6-hydroxymethyldihydropteridine diphosphok 4 048 kb 4 052 kb 4 056 kb 4 060 kb 4 064 kb 4 068 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-annotationN-acetylmuramoyl-L-alanine amidase
Revised (this work)N-acetylmuramoyl-L-alanine amidase. Pfam: Amidase_2 (PF01510.31), Rv3766_C (PF27131.1).
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) never studied

No publication in PubMed mentions this gene in its title or abstract — not under its H37Rv locus tag, nor under any of its ortholog identifiers (M. bovis, M. marinum, M. smegmatis, M. leprae, M. abscessus). The atlas annotation rests on sequence/structure evidence, not on a primary study of this gene.

A verified absence of literature is itself information: it flags an annotation with no primary study behind it. 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 0.83 (95% CI -0.12 to 2.51). 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 (COG category, 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 Mb3625 · 99.6% identity
M. smegmatis MSMEG_5315 · 55.5% identity
M. orygis RJtmp_003702 · 99.6% identity
M. abscessus MAB_4807 · 53.0% 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 I6Y3Z2 TrEMBL · unreviewed · Evidence at protein level
UniProt nameN-acetylmuramoyl-L-alanine amidase domain-containing protein

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category M Cell wall / membrane / envelope biogenesis
V Defense mechanisms
eggNOG descriptionN-acetylmuramoyl-L-alanine amidase
Orthologous groupCOG3023

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 1.802 · diversifying/relaxed
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 11 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) Corynebacteriales

M. canettii dN/dS (deep-divergence selection) 0.657 (low power) · 3 consensus substitution(s)
low power (3 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable
Genus-wide presence (~53 non-MTBC Mycobacterium) present in 6/53 (11%) · mean identity 58.5% · 2/4 closest MTBAP relatives
present in a subset of the genus (6/53 NTM; in 2 of the 4 closest MTBAP relatives) — partial/intermediate conservation
Phylostratum (deepest detected homolog) MTBC-specific Mycobacterium Mycobacteriaceae Corynebacteriales Actinomycetia Bacteria
detected in 3/13 non-Mycobacterium reference genomes (down to Corynebacteriales) · mean identity 43.6%
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) 16 in the ORF — 0 in the essential state, 0 growth-defect, 16 non-essential, 0 growth-advantage. Saturation 0.938, mean read count 111.933333333. 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)

Conditionlog2FCqEffect
fitness after prolonged in vitro passage (in vitro passage) -2.170.02 required

Conditional fitness of transposon-disruption mutants across 1 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 8 of 16 independent MS datasets
Integrated abundance1.98 ppm · rank 3175/3519 (9.8th 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.

Physico-chemical properties (computed, ProtParam)

Length275 aa
Molecular weight30.7 kDa
Theoretical pI6.32
GRAVY-0.507 (hydrophilic)
Aliphatic index82.7
Aromaticity0.076
Instability index33.3 (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
Amidase_2PF01510.31 2.0e-1737–173 N-acetylmuramoyl-L-alanine amidase
Rv3766_CPF27131.1 2.2e-10218–256 Rv3766 C-terminal domain

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 92.7

PDB hitprobTM-scoreE-valueDescription
4bol-assembly1_B 1.00 0.69 5.7e-06 sig 4bol-assembly1_B Crystal structure of AmpDh2 from Pseudomonas aeruginosa in complex with pentapeptide
2y28-assembly3_C 1.00 0.60 5.7e-06 sig 2y28-assembly3_C crystal structure of Se-Met AmpD derivative
4bxe-assembly1_A 1.00 0.63 2.9e-05 sig 4bxe-assembly1_A CRYSTAL STRUCTURE OF AMPDH3 FROM PSEUDOMONAS AERUGINOSA IN COMPLEX WITH ANHYDROMURAMIC PENTAPEPTIDE
3d2y-assembly1_A 1.00 0.64 4.8e-05 sig 3d2y-assembly1_A Complex of the N-acetylmuramyl-L-alanine amidase AmiD from E.coli with the substrate anhydro-N-acetylmuramic acid-L-Ala-D-gamma-Glu-L-Lys
3rdr-assembly1_A 1.00 0.71 1.9e-04 sig 3rdr-assembly1_A Structure of the catalytic domain of XlyA

Foldseek search of the AlphaFold DB model (mean pLDDT 92.7, 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)

Upstream (5' on genome)lpqF (+ strand, 146 bp gap)
Downstream (3' on genome)PE_PGRS59 (- strand, 46 bp gap)

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: Rv1230c (membrane protein), medium confidence from genomic context alone (score 685 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv1230c membrane protein 704 685 ctx cooccurence:683
Rv1443c hyp hypothetical protein 675 675 ctx cooccurence:675
Rv3879c espK ESX-1 secretion-associated protein EspK 673 672 ctx cooccurence:669
Rv3877 eccD1 ESX-1 secretion system protein EccD1 629 630 ctx cooccurence:628
Rv1288 hyp hypothetical protein 669 627 ctx cooccurence:622
Rv1921c lppF lipoprotein LppF 623 624 ctx cooccurence:617
Rv3882c eccE1 ESX-1 secretion system protein EccE1 623 623 ctx cooccurence:622
Rv2164c hyp hypothetical protein 621 621 ctx cooccurence:616
Rv1651c PE_PGRS30 PE-PGRS family protein PE_PGRS30 597 595 ctx cooccurence:592
Rv0341 iniB isoniazid inducible protein IniB 565 566 ctx cooccurence:560
Rv3593 lpqF lipoprotein LpqF 578 563 ctx neighborhood:495
Rv0613c hyp hypothetical protein 554 554 ctx cooccurence:553
Rv3365c hyp hypothetical protein 537 535 ctx cooccurence:529
Rv2735c hyp hypothetical protein 526 526 ctx cooccurence:525
Rv3472 hyp hypothetical protein 524 525 ctx cooccurence:511

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: N-acetylmuramoyl-L-alanine amidase
  • Pfam (hmmscan --cut_ga): Amidase_2 PF01510.31 (E=2e-17), Rv3766_C PF27131.1 (E=2e-10)
  • (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_218111.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Amidase_2 (PF01510.31), Rv3766_C (PF27131.1)
  • 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 COG3023
  • Curated reference: UniProt I6Y3Z2 (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 92.7)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 63 functional partner(s); context anchor Rv1230c
  • 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_003813|Rv3594|
MGWIGDPIWLEEVLRPALGERLRVLDGWRERGHGDFRDIRGVMWHHTGNSRETAKSIARGRPDLPGPLANLHIAHSGVVTIVAVGVCWHAGRGSYPWLPTDNANWHMIGVECAWPTIRRDGSYDAGERWPDAQIVSMRDVAAALTLKLGYGPERNIGHKEYAGAAQGKWDPGNLSMDWFRAEVAKDTRGEFDHPLTPPPAVIARPPILPKPRNPRDDRILLEEVWDQLRGIEGRGWPVLGDKTIVDYLAELGNKVDALAAKLDAREGLDRPSDTR