embR Resolved · high auto-curated

H37Rv Rv1267c · MTBC0 mtbc0_001357 · 388 aa · 1425164–1426330 MTBC0 (-) · RefSeq NP_215783.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)transcriptional regulator EmbR
MTBC0 PGAP re-annotationresponse regulator transcription factor EmbR
Revised (this work)Response regulator transcription factor EmbR. Pfam: Trans_reg_C (PF00486.35), BTAD (PF03704.24), Yop-YscD_cpl (PF16697.11), FHA (PF00498.32).
Functional category (TubercuList)regulatory proteins

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) 33 publications

33 TB publications mention this gene. 33 publication(s) discuss this gene (33 in a M. tuberculosis context, 5 in other mycobacteria — M. smegmatis (4), M. abscessus (1)).

Most recent 5 of 33.
PublicationDate
Interred mechanisms of resistance and host immune evasion revealed through network-connectivity analysis of M. tuberculosis complex graph pangenome. doi:10.1128/msystems.00499-24 2025
The implications of mutations in multiple genes associated with ethambutol resistance among multidrug-resistant tuberculosis isolates from China. doi:10.1186/s12866-025-03821-y 2025
Analysis of molecular resistance and associated risk factors in tuberculosis. doi:10.1186/s12879-025-10615-0 2025
Genetic diversities and drug resistance in Mycobacterium bovis isolates from zoonotic tuberculosis using whole genome sequencing. doi:10.1186/s12864-024-10909-8 2024
Mutations in embB406 Are Associated with Low-Level Ethambutol Resistance in Canadian Mycobacterium tuberculosis Isolates. doi:10.3390/antibiotics13070624 2024

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 0.79 (95% CI -0.52 to 3.09). 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 functionInvolved in transcriptional mechanism. Thought to regulate the biosynthesis of the mycobacterial cell wall arabinan and resistance to ethambutol (EMB; dextro-2,2'-(ethylenediimino)-DI-1-butanol), regulating EMBA|Rv3794 and EMBB|Rv3795.

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 Mb1298c · 100.0% identity
M. marinum MMAR_4155 · 87.7% identity
M. smegmatis MSMEG_1963 · 39.9% identity
M. orygis RJtmp_001334 · 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 P9WGJ9 SwissProt · reviewed · Evidence at protein level
UniProt nameTranscriptional regulatory protein EmbR
Curated functionPositively regulates the transcription of the embCAB operon. Exhibits ATPase and GTPase activities.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category K Transcription
Preferred nameembR
eggNOG descriptioninvolved in transcriptional mechanism. thought to regulate the biosynthesis of the mycobacterial cell wall arabinan and resistance to ethambutol (Emb
Orthologous groupCOG1716
Gene Ontology (41) GO:0003674, GO:0003676, GO:0003677, GO:0003824, GO:0003924, GO:0005488, GO:0005575, GO:0005618, GO:0005623, GO:0005886, GO:0006355, GO:0008150 +29 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 0.582 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 3 synonymous, 5 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) · 1 consensus substitution(s)
low power (1 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable
Genus-wide presence (~53 non-MTBC Mycobacterium) present in 46/53 (87%) · mean identity 76.8% · 4/4 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 5/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 42.9%
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) 21 in the ORF — 0 in the essential state, 0 growth-defect, 21 non-essential, 0 growth-advantage. Saturation 0.952, mean read count 106.95. 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.

Proteomics (mass spectrometry) detected

MS detectiondetected in 13 of 16 independent MS datasets
Integrated abundance115.0 ppm · rank 1196/3519 (66.0th 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)

Length388 aa
Molecular weight41.9 kDa
Theoretical pI6.71
GRAVY-0.168 (hydrophilic)
Aliphatic index93.6
Aromaticity0.057
Instability index30.7 (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
Trans_reg_CPF00486.35 1.8e-1031–103 Transcriptional regulatory protein, C terminal
BTADPF03704.24 2.2e-49110–255 Bacterial transcriptional activator domain
Yop-YscD_cplPF16697.11 1.4e-10297–378 Inner membrane component of T3SS, cytoplasmic domain
FHAPF00498.32 1.0e-17308–371 FHA domain

Experimental structures (Protein Data Bank) 2 solved

PDBMethodResolutionCoverage
2ff4 X-ray diffraction 1.9 Å 100%
2fez X-ray diffraction 2.0 Å 100%

Experimentally solved structures mapped from the UniProt accession via PDBe/SIFTS (2 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 92.1

PDB hitprobTM-scoreE-valueDescription
2ff4-assembly1_A 1.00 0.98 2.3e-56 sig 2ff4-assembly1_A Mycobacterium tuberculosis EmbR in complex with low affinity phosphopeptide
8hvr-assembly1_J 1.00 0.89 7.5e-14 sig 8hvr-assembly1_J Cryo-EM structure of AfsR-dependent transcription activation complex with afsS promoter
3poa-assembly1_A 1.00 0.92 2.8e-07 sig 3poa-assembly1_A Structural and functional analysis of phosphothreonine-dependent FHA domain interactions
6i2p-assembly1_D 1.00 0.90 6.0e-07 sig 6i2p-assembly1_D Crystal structure of the Mycobacterium tuberculosis PknB kinase domain (L33E mutant) in complex with its substrate GarA
3oun-assembly1_A 1.00 0.91 8.4e-07 sig 3oun-assembly1_A Crystal structure of the FhaA FHA domain complexed with the intracellular domain of Rv3910

Foldseek search of the AlphaFold DB model (mean pLDDT 92.1, 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)pknH (- strand, 340 bp gap)
Downstream (3' on genome)Rv1268c (- strand, 310 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: Rv0894 (transcriptional regulator), high confidence from genomic context alone (score 967 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0894 transcriptional regulator 968 967 ctx fusion:774 coexpression:800
Rv2488c LuxR family transcriptional regulator 935 931 ctx fusion:454 coexpression:859
Rv0339c iniR transcriptional regulator 899 897 ctx cooccurence:506 coexpression:800
Rv3263 DNA methylase 875 876 coexpression:850
Rv1963c mce3R transcriptional repressor Mce3R 870 868 coexpression:815
Rv0691c mftR mycofactocin biosynthesis transcriptional regulator MftR 863 860 coexpression:860
Rv3167c TetR family transcriptional regulator 863 860 coexpression:860
Rv1931c transcriptional regulator 862 860 coexpression:860
Rv1151c cobB NAD-dependent protein deacylase 860 860 coexpression:860
Rv0212c nadR transcriptional regulator NadR 860 860 coexpression:860
Rv1674c transcriptional regulator 860 860 coexpression:860
Rv1675c cmr HTH-type transcriptional regulator Cmr 860 860 coexpression:860
Rv1027c kdpE transcriptional regulator KdpE 864 859 coexpression:859
Rv3736 AraC/XylS family transcriptional regulator 859 859 coexpression:859
Rv3055 TetR family transcriptional regulator 860 857 coexpression:804

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: transcriptional regulator EmbR
  • MTBC0 PGAP product: response regulator transcription factor EmbR
  • Pfam (hmmscan --cut_ga): Trans_reg_C PF00486.35 (E=2e-10), BTAD PF03704.24 (E=2e-49), Yop-YscD_cpl PF16697.11 (E=1e-10), FHA PF00498.32 (E=1e-17)
  • (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_215783.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Trans_reg_C (PF00486.35), BTAD (PF03704.24), Yop-YscD_cpl (PF16697.11), FHA (PF00498.32)
  • 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 COG1716
  • Curated reference: UniProt P9WGJ9 (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 92.1)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 122 functional partner(s); context anchor Rv0894
  • 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_001357|Rv1267c|embR
MAGSATVEKRLDFGLLGPLQMTIDGTPVPSGTPKQRAVLAMLVINRNRPVGVDALITALWEEWPPSGARASIHSYVSNLRKLLGGAGIDPRVVLAAAPPGYRLSIPDNTCDLGRFVAEKTAGVHAAAAGRFEQASRHLSAALREWRGPVLDDLRDFQFVEPFATALVEDKVLAHTAKAEAEIACGRASAVIAELEALTFEHPYREPLWTQLITAYYLSDRQSDALGAYRRVKTTLADDLGIDPGPTLRALNERILRQQPLDAKKSAKTTAAGTVTVLDQRTMASGQQAVAYLHDIASGRGYPLQAAATRIGRLHDNDIVLDSANVSRHHAVIVDTGTNYVINDLRSSNGVHVQHERIRSAVTLNDGDHIRICDHEFTFQISAGTHGGT