lysE Resolved · high auto-curated

H37Rv Rv1986 · MTBC0 mtbc0_002110 · 199 aa · 2253624–2254223 MTBC0 (+) · RefSeq NP_216502.1

Genomic neighbourhood (genome browser)

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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)amino acid transporter
MTBC0 PGAP re-annotationL-lysine exporter
Revised (this work)L-lysine exporter. Pfam: LysE (PF01810.25).
Functional category (TubercuList)cell wall and cell processes

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) 149 publications

149 TB publications mention this gene. 149 publication(s) discuss this gene (116 in a M. tuberculosis context, 45 in other mycobacteria — M. smegmatis (20), M. leprae (10), M. marinum (6), M. abscessus (4)).

Most recent 5 of 149.
PublicationDate
pH-responsive substrate switching in mycobacterial type VII ESX secretion. doi:10.1128/msphere.00056-26 2026
Bacteriophages target membrane-anchored glycopolymers to promote host cell lysis and progeny release. doi:10.1073/pnas.2606687123 2026
A novel phage satellite class induces prophage excision in Mycolicibacterium aichiense. doi:10.1016/j.virol.2026.110911 2026
pH-responsive substrate switching in mycobacterial Type VII ESX secretion. doi:10.64898/2026.02.04.703728 2026
A novel phage satellite class induces prophage excision in Mycolicibacterium aichiense. doi:10.64898/2025.12.02.691453 2025

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.

Conditional expression context (iModulons)

Member of 1 independently-modulated gene set(s): WhiB6 (whiB6).

iModulon membership (independently-modulated gene sets from a 647-sample RNA-seq compendium): the conditional co-expression context. Co-expression is a regulatory context, NOT a molecular function. Source: iModulonDB / modulome_mtb (Yoo 2022).

CRISPRi vulnerability

Vulnerability index 1.32 (95% CI -0.01 to 3.60). 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 functionUnknown; possibly involved in transport of lysine across the membrane.

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 Mb2008 · 100.0% identity
M. smegmatis MSMEG_0467 · 73.2% identity
M. orygis RJtmp_002050 · 100.0% identity
M. abscessus MAB_4386 · 65.6% 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 P9WK31 SwissProt · reviewed · Evidence at transcript level
UniProt nameLysine exporter LysE
Curated functionCatalyzes the efflux of L-lysine.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
Preferred namelysE
eggNOG descriptionLysine exporter protein LysE YggA
Orthologous groupCOG1279
KEGG orthology K06895
Gene Ontology (49) GO:0003333, GO:0003674, GO:0005215, GO:0005342, GO:0005575, GO:0005623, GO:0005886, GO:0006810, GO:0006811, GO:0006812, GO:0006820, GO:0006865 +37 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 0.389 · purifying
Polymorphic sites (≥ 0.1% of strains) 5 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) Bacteria

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 6/53 (11%) · mean identity 65.9% · 1/4 closest MTBAP relatives
present in a subset of the genus (6/53 NTM; in 1 of the 4 closest MTBAP relatives) — partial/intermediate conservation
Phylostratum (deepest detected homolog) MTBC-specific Mycobacterium Mycobacteriaceae Corynebacteriales Actinomycetia Bacteria
detected in 11/13 non-Mycobacterium reference genomes (down to Bacteria) · mean identity 47.3%
detected down to outside the phylum (Proteobacteria/Firmicutes controls) — a universally conserved, ancient bacterial 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) 9 in the ORF — 0 in the essential state, 0 growth-defect, 9 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 102.777777778. 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 9 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 9 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) not detected

Not detected in the mass-spectrometry datasets integrated by PaxDb. This is not evidence of absence: low-abundance, condition-specific, or MS-refractory proteins (e.g. small, highly hydrophobic, or repetitive PE/PPE families with few tryptic peptides) are systematically under-sampled.

Predicted localisation (DeepTMHMM + lipobox) lipoprotein

Predictionpredicted lipoprotein (lipobox + signal peptide)
DeepTMHMM classTM
TM helices (DeepTMHMM)6
Lipoboxsignal-peptidase-II lipobox; lipidated Cys near position 12

Transmembrane topology and signal peptide from DeepTMHMM (deep-learning reference predictor); lipoproteins from a (myco)bacterial lipobox motif. A sequence-based prediction of subcellular context.

Physico-chemical properties (computed, ProtParam)

Length199 aa
Molecular weight20.8 kDa
Theoretical pI9.87
GRAVY0.967 (hydrophobic)
Aliphatic index128.0
Aromaticity0.09
Instability index20.9 (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
LysEPF01810.25 7.9e-4014–197 LysE type translocator

Genomic context (neighbours & predicted operon)

Upstream (5' on genome)Rv1985c (- strand, 108 bp gap)
Downstream (3' on genome)Rv1987 (+ strand, 415 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).

Transcriptional regulation (signed TRN: ChIP-seq + TFOE)

Regulated by (8 TF) Rv0023 (activates) · Rv0324 (represses) · Rv0576 (represses) · mmpR5 (activates) · Rv1049 (activates) · cmtR (represses) · Rv2989 (activates) · tcrX (activates)

Regulatory edges from the ISB signed transcriptional regulatory network (TF ChIP-seq binding, Minch 2015 + TF-overexpression response, Rustad 2014). An edge is regulatory evidence (binding and/or expression change), not necessarily direct. For a "hypothetical", membership in a known regulon (e.g. DosR dormancy, PhoP virulence) is a strong physiological-context lead.

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: lysG (HTH-type transcriptional regulator), high confidence from genomic context alone (score 905 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1985c lysG HTH-type transcriptional regulator 973 905 ctx neighborhood:595 cooccurence:774 textmining:727
Rv3291c lrpA transcriptional regulator LrpA 604 193 textmining:530
Rv2658c prophage protein 444 55 textmining:436
Rv1404 transcriptional regulator 428 50 textmining:423
Rv1979c permease 513 48 textmining:510
Rv0755A Rv0755A, len: 61 aa. Putative transposase (possibly gene fragment), similar to C-terminal part of Q9EZM2|ISMav2|AF286339_1 putative transpos 433 43 textmining:432

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: amino acid transporter
  • MTBC0 PGAP product: L-lysine exporter
  • Pfam (hmmscan --cut_ga): LysE PF01810.25 (E=8e-40)
  • (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_216502.1)
  • Domains: Pfam-A via hmmscan --cut_ga — LysE (PF01810.25)
  • 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 COG1279
  • Curated reference: UniProt P9WK31 (SwissProt, reviewed; Evidence at transcript 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 89.0)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 6 functional partner(s); context anchor lysG
  • Essentiality: genome-wide transposon mutagenesis in H37Rv — DeJesus et al. 2017 (mBio, doi:10.1128/mBio.02133-16, CC BY)
  • 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)
  • Transcriptional regulation: ISB signed TRN — TF ChIP-seq (Minch et al. 2015, doi:10.1038/ncomms6829) + TF overexpression (Rustad et al. 2014, doi:10.1186/gb-2014-15-11-502)
  • Physico-chemical properties: ExPASy ProtParam method via Biopython (Gasteiger et al. 2005), computed from the MTBC0 sequence
  • Predicted localisation: DeepTMHMM (Hallgren et al. 2022, doi:10.1101/2022.04.08.487609) for transmembrane topology and signal peptide; (myco)bacterial lipobox (Sutcliffe & Harrington 2004, doi:10.1099/mic.0.26804-0)
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002110|Rv1986|lysE
MNSPLVVGFLACFTLIAAIGAQNAFVLRQGIQREHVLPVVALCTVSDIVLIAAGIAGFGALIGAHPRALNVVKFGGAAFLIGYGLLAARRAWRPVALIPSGATPVRLAEVLVTCAAFTFLNPHVYLDTVVLLGALANEHSDQRWLFGLGAVTASAVWFATLGFGAGRLRGLFTNPGSWRILDGLIAVMMVALGISLTVT