adoK Family assigned · medium auto-curated

H37Rv Rv2202c · MTBC0 mtbc0_002338 · 324 aa · 2493210–2494184 MTBC0 (-) · RefSeq NP_216718.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)adenosine kinase
MTBC0 PGAP re-annotationcarbohydrate kinase family protein
Revised (this work)Carbohydrate kinase family protein. Pfam: PfkB (PF00294.30).
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) 4 publications

4 TB publications mention this gene. 4 publication(s) discuss this gene (5 in a M. tuberculosis context, 1 in other mycobacteria — ).

PublicationDate
An N-acetyltransferase required for EsxA N-terminal protein acetylation and virulence in Mycobacterium marinum. doi:10.1101/2023.03.14.532585 2023
Cordycepin kills Mycobacterium tuberculosis through hijacking the bacterial adenosine kinase. doi:10.1371/journal.pone.0218449 2019
Purine metabolism in Mycobacterium tuberculosis as a target for drug development. doi:10.2174/138161207780162863 2007
Evaluation of 3-deaza-adenosine analogues as ligands for adenosine kinase and inhibitors of Mycobacterium tuberculosis growth. doi:10.1093/jac/dkl448 2007
Identification and characterization of a unique adenosine kinase from Mycobacterium tuberculosis. doi:10.1128/JB.185.22.6548-6555.2003 2003

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.

Post-translational modifications

1 reported modified residue(s): N-acetylthreonine @2.

Experimentally reported post-translational modification(s). A phosphosite indicates the protein is expressed and is a substrate of the M. tuberculosis Ser/Thr/Tyr kinase signalling network — a regulatory context, NOT a molecular function. Source: UniProt (Modified residue features; PTM sites curated from the M. tuberculosis literature).

CRISPRi vulnerability

Vulnerability index -2.31 (95% CI -2.65 to -1.94). 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)

Mycobrowser functionAdenosine phosphorylation
Mycobrowser EC 2.7.1.20 · agrees with the atlas

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 Mb2225c · 99.7% identity
M. leprae ML0873 · 83.9% identity
M. marinum MMAR_3246 · 91.7% identity
M. smegmatis MSMEG_4270 · 78.7% identity
M. orygis RJtmp_002273 · 99.7% identity
M. abscessus MAB_1959 · 76.8% 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 P9WID5 SwissProt · reviewed · Evidence at protein level
UniProt nameAdenosine kinase
EC (curated) EC 2.7.1.20
Curated functionCatalyzes the phosphorylation of adenosine to adenosine monophosphate (AMP). Can also catalyze the phosphorylation of the adenosine analog 2-methyladenosine (methyl-Ado) to methyl-AMP, the first step in the metabolism of this compound to an active form that displays antitubercular activity. Is not active on guanosine, inosine, deoxyadenosine, cytidine, uridine, or thymidine. Prefers dGTP and GTP to ATP as phosphate donors in vitro.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category G Carbohydrate transport and metabolism
Preferred nameadoK
eggNOG descriptionRibokinase
Orthologous groupCOG0524
EC number EC 2.7.1.20
KEGG orthology K00856
KEGG pathways map00230, map01100
Gene Ontology (109) GO:0000166, GO:0000287, GO:0001882, GO:0001883, GO:0003674, GO:0003824, GO:0004001, GO:0005488, GO:0005524, GO:0005525, GO:0005575, GO:0005622 +97 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 0.086 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 8 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

M. canettii dN/dS (deep-divergence selection) 0.0 (low power) · 2 consensus substitution(s)
low power (2 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 86.5% · 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 6/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 65.6%
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) GD — not strictly essential

DeJesus 2017 callGD · growth-defect
What the call meansgrowth-defect: insertions tolerated but fitness reduced; NOT essential
TA sites (Himar1) 20 in the ORF — 0 in the essential state, 19 growth-defect, 1 non-essential, 0 growth-advantage. Saturation 0.300, mean read count 8.33333333333. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction.
Caveat`essential: true` here is the broad union (ES+ESD+GD) kept for backward compatibility; this gene is NOT strictly essential. Read n_sites_* before writing anything about essentiality.

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.

Chemical-genetic target & druggability (PROSPECT) hypomorph tool strain

This gene is part of the PROSPECT collection of TetON transcriptional-knockdown (hypomorph) strains of essential M. tuberculosis genes, built as a sensitised background for chemical-genetic mechanism-of-action deconvolution. Being in the panel means the gene is an essential / vulnerable target for which a validated knockdown tool strain exists.

Hypomorph strainadoK-FLAG-tetOn-10 (TetON promoter 10)
Baseline knockdown fitness3.051 median doublings (across 6 screen pool(s)) — fewer doublings = stronger growth defect on knockdown
Used in target deconvolutionyes (informs phenotypic-cluster / MOA assignment)

Panel membership reflects essentiality/vulnerability and the availability of a genetic tool, not a specific molecular function; it never changes the verdict here. Source: Bond AN et al., Nat Commun 2025;16:9673 (doi:10.1038/s41467-025-64662-x); PROSPECT chemical-genetic platform.

Mutant phenotypes (conditional Tn-seq, MtbTnDB)

Conditionlog2FCqEffect
altered fitness under Isoniazid (drug exposure) +8.430.0 disruption advantageous
altered fitness under Isoniazid (drug exposure) +6.070.0051 disruption advantageous
Differential genetic requirements of clinical Mtb strain (ID=631) from East Asian lineage (compared to H37Rv control) (strain background) +4.220.0 required
Differential genetic requirements of clinical Mtb strain (ID=621) from East Asian lineage (compared to H37Rv control) (strain background) +4.170.0 required
Differential genetic requirements of clinical Mtb strain (ID=662) from East Asian lineage (compared to H37Rv control) (strain background) +3.570.0 required
Differential genetic requirements of clinical Mtb strain (ID=641) from Indo-Oceanic lineage (compared to H37Rv control) (strain background) +2.940.0 required
Differential genetic requirements of clinical Mtb strain (ID=667) from Indo-Oceanic lineage (compared to H37Rv control) (strain background) +2.020.014 required
Differential genetic requirements of clinical Mtb strain (ID=663) from Euro-American lineage (compared to H37Rv control) (strain background) +1.900.013 required

Conditional fitness of transposon-disruption mutants across 8 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 15 of 16 independent MS datasets
Integrated abundance1084.0 ppm · rank 211/3519 (94.0th 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)

Length324 aa
Molecular weight34.5 kDa
Theoretical pI4.75
GRAVY0.144 (hydrophobic)
Aliphatic index96.4
Aromaticity0.071
Instability index26.8 (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
PfkBPF00294.30 3.4e-5215–295 pfkB family carbohydrate kinase

Experimental structures (Protein Data Bank) 13 solved

PDBMethodResolutionCoverage
2pkf X-ray diffraction 1.5 Å 100%
4o1g X-ray diffraction 1.5 Å 100%
6c9v X-ray diffraction 1.7 Å 100%
2pkm X-ray diffraction 1.9 Å 100%
2pkn X-ray diffraction 1.9 Å 100%
2pkk X-ray diffraction 1.93 Å 100%
6c9q X-ray diffraction 1.95 Å 100%
6c9p X-ray diffraction 2.0 Å 100%

Experimentally solved structures mapped from the UniProt accession via PDBe/SIFTS (13 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 96.6

PDB hitprobTM-scoreE-valueDescription
6c9r-assembly1_B 1.00 0.98 2.4e-65 sig 6c9r-assembly1_B Mycobacterium tuberculosis adenosine kinase bound to (2R,3S,4R,5R)-2-(hydroxymethyl)-5-(6-(thiophen-3-yl)-9H-purin-9-yl)tetrahydrofuran-3,4-diol
6c67-assembly1_B 1.00 0.99 7.4e-63 sig 6c67-assembly1_B Mycobacterium tuberculosis adenosine kinase bound to iodotubercidin
6c9p-assembly1_B 1.00 0.98 8.7e-63 sig 6c9p-assembly1_B Mycobacterium tuberculosis adenosine kinase bound to 6-methylmercaptopurine riboside
6c9n-assembly1_A 1.00 0.98 1.6e-62 sig 6c9n-assembly1_A Mycobacterium tuberculosis adenosine kinase bound to sangivamycin
6c67-assembly1_A 1.00 0.98 2.6e-62 sig 6c67-assembly1_A Mycobacterium tuberculosis adenosine kinase bound to iodotubercidin

Foldseek search of the AlphaFold DB model (mean pLDDT 96.6, 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)asnB (+ strand, 97 bp gap)
Downstream (3' on genome)Rv2203 (+ strand, 203 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: Rv2203 (membrane protein), high confidence from genomic context alone (score 758 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2584c apt exp adenine phosphoribosyltransferase 963 948 database:900
Rv0777 purB exp adenylosuccinate lyase PurB 945 922 database:900
Rv0733 adk exp adenylate kinase 974 920 database:900 textmining:691
Rv3393 iunH exp nucleoside hydrolase 925 915 database:900
Rv3313c add exp adenosine deaminase 991 914 database:900 textmining:901
Rv3307 deoD exp purine nucleoside phosphorylase 938 914 database:900
Rv0805 cpdA exp 3',5'-cyclic adenosine monophosphate phosphodiesterase CpdA 906 906 database:900
Rv2203 membrane protein 758 758 ctx neighborhood:757
Rv1603 hisA 1-(5-phosphoribosyl)-5-((5-phosphoribosylamino)methylideneamino)imidazole-4-carboxamide isomerase 713 702 coexpression:692
Rv0498 hyp hypothetical protein 612 560 coexpression:535
Rv1752 hyp hypothetical protein 519 458 coexpression:427
Rv3248c sahH adenosylhomocysteinase 745 452 textmining:554
Rv1392 metK S-adenosylmethionine synthetase 512 450
Rv0357c purA adenylosuccinate synthetase 600 447
Rv1416 ribH 6,7-dimethyl-8-ribityllumazine synthase 513 447 coexpression:429

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: adenosine kinase
  • MTBC0 PGAP product: carbohydrate kinase family protein
  • Pfam (hmmscan --cut_ga): PfkB PF00294.30 (E=3e-52)
  • (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_216718.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PfkB (PF00294.30)
  • 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 COG0524
  • Curated reference: UniProt P9WID5 (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 96.6)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 43 functional partner(s); context anchor Rv2203
  • 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)
  • 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_002338|Rv2202c|adoK
MTIAVTGSIATDHLMRFPGRFSEQLLPEHLHKVSLSFLVDDLVMHRGGVAGNMAFAIGVLGGEVALVGAAGADFADYRDWLKARGVNCDHVLISETAHTARFTCTTDVDMAQIASFYPGAMSEARNIKLADVVSAIGKPELVIIGANDPEAMFLHTEECRKLGLAFAADPSQQLARLSGEEIRRLVNGAAYLFTNDYEWDLLLSKTGWSEADVMAQIDLRVTTLGPKGVDLVEPDGTTIHVGVVPETSQTDPTGVGDAFRAGFLTGRSAGLGLERSAQLGSLVAVLVLESTGTQEWQWDYEAAASRLAGAYGEHAAAEIVAVLA