Rv1232c Resolved · high auto-curated

H37Rv Rv1232c · MTBC0 mtbc0_001321 · 435 aa · 1383305–1384612 MTBC0 (-) · RefSeq NP_215748.1

Genomic neighbourhood (genome browser)

Open in full genome browser →
+ strand − strand sigE (Rv1221) — requalified: RNA polymerase sigma factor SigE rseA (Rv1222) — requalified: anti-sigma E factor RseA tatB (Rv1224) — requalified: Sec-independent protein translocase protein TatB Rv1225c (Rv1225c) — family_assigned: HAD-IIA family hydrolase Rv1225c Rv1226c (Rv1226c) — family_assigned: PH domain-containing protein Rv1226c Rv1227c (Rv1227c) — family_assigned: PH domain-containing protein lpqX (Rv1228) — dark: hypothetical protein mrp (Rv1229c) — family_assigned: Mrp/NBP35 family ATP-binding protein mrp Rv1230c (Rv1230c) — family_assigned: lytic transglycosylase domain-containing protein Rv1230c Rv1231c (Rv1231c) — family_assigned: DUF1003 domain-containing protein Rv1232c (Rv1232c) — requalified: magnesium transporter Rv1232c Rv1233c (Rv1233c) — family_assigned: DUF4190 domain-containing protein Rv1234 (Rv1234) — requalified: general stress protein lpqY (Rv1235) — family_assigned: trehalose ABC transporter substrate-binding protein LpqY lpqY sugA (Rv1236) — family_assigned: trehalose ABC transporter permease SugA sugA sugB (Rv1237) — family_assigned: trehalose ABC transporter permease SugB sugB sugC (Rv1238) — family_assigned: trehalose ABC transporter ATP-binding protein SugC sugC corA (Rv1239c) — requalified: magnesium/cobalt transporter CorA corA mdh (Rv1240) — requalified: malate dehydrogenase mdh vapB33 (Rv1241) — requalified: type II toxin-antitoxin system antitoxin VapB33 vapC33 (Rv1242) — family_assigned: type II toxin-antitoxin system VapC family toxin lpqZ (Rv1244) — family_assigned: glycine betaine ABC transporter substrate-binding protein 1 372 kb 1 376 kb 1 380 kb 1 384 kb 1 388 kb 1 392 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-annotationmagnesium transporter
Revised (this work)Magnesium transporter. Pfam: SH3_actinomycetes (PF26205.1), MgtE_N (PF03448.23), CBS (PF00571.34).
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.

Genomic-neighbour overlap (structural caveat) co-directional · 0 % of gene

NeighbourRv1231c (Rv1231c, - strand)
Overlap4 bp, 0 % of this gene's length

co-directional overlap: ordinary (e.g. shared stop/start codons in an operon), not the Rv2438A-type artefact P20.1, derived from GFF3 gene coordinates, 2026-08-03.

Conditional expression context (iModulons)

Member of 1 independently-modulated gene set(s): Central Carbon Metabolism.

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 0.47 (95% CI -1.26 to 2.88). 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 Mb1264c · 99.8% identity
M. marinum MMAR_4209 · 87.3% identity
M. smegmatis MSMEG_5065 · 78.0% identity
M. abscessus MAB_1524c · 72.9% 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 O86315 TrEMBL · unreviewed · Evidence at protein level
UniProt nameConserved protein

UniProt still lists this protein as Conserved protein; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category P Inorganic ion transport and metabolism
Preferred namemgtE
eggNOG descriptionCBS domain
Orthologous groupCOG2239

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 0.308 · purifying
Polymorphic sites (≥ 0.1% of strains) 6 synonymous, 5 missense, 0 nonsense, 1 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 0.34% of strains (497) · clonal

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) inf (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 50/53 (94%) · mean identity 83.7% · 4/4 closest MTBAP relatives
conserved across the genus (present in 50/53 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 10/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 57.1%
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) 11 in the ORF — 0 in the essential state, 0 growth-defect, 11 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 211.727272727. 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 12 of 16 independent MS datasets
Integrated abundance90.3 ppm · rank 1364/3519 (61.3th 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)

Length435 aa
Molecular weight47.3 kDa
Theoretical pI5.2
GRAVY-0.034 (hydrophilic)
Aliphatic index107.5
Aromaticity0.034
Instability index38.3 (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
SH3_actinomycetesPF26205.1 3.3e-2292–164 Actinomycetes SH3 domain
MgtE_NPF03448.23 9.2e-23186–285 MgtE intracellular N domain
CBSPF00571.34 7.7e-08356–410 CBS domain

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 87.4

PDB hitprobTM-scoreE-valueDescription
5x9g-assembly1_A 1.00 0.86 5.5e-18 sig 5x9g-assembly1_A Crystal structure of the cytosolic domain of the Mg2+ channel MgtE in complex with ATP
2oux-assembly1_B 1.00 0.87 1.7e-17 sig 2oux-assembly1_B Crystal structure of the soluble part of a magnesium transporter
8gpv-assembly1_A-2 1.00 0.89 1.6e-16 sig 8gpv-assembly1_A-2 Cytoplasmic domain structure of the MgtE Mg2+ channel from Clostridiales bacterium
5x9h-assembly1_A 1.00 0.84 8.3e-17 sig 5x9h-assembly1_A Crystal structure of the Mg2+ channel MgtE in complex with ATP
8gps-assembly1_A-2 1.00 0.87 3.1e-15 sig 8gps-assembly1_A-2 Cytoplasmic domain structure of the MgtE Mg2+ channel from Chryseobacterium hispalense

Foldseek search of the AlphaFold DB model (mean pLDDT 87.4, 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 2

Upstream (5' on genome)Rv1231c (- strand, -4 bp gap)
Downstream (3' on genome)Rv1233c (- strand, 61 bp gap)
Predicted operon Rv1231c · Rv1232c

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: Rv1231c (membrane protein), high confidence from genomic context alone (score 965 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv1231c membrane protein 965 965 ctx neighborhood:882 cooccurence:713
Rv1233c hyp hypothetical protein 804 804 ctx neighborhood:801
Rv1230c membrane protein 762 762 ctx neighborhood:761
Rv1229c mrp multiple resistance/pH adaptation protein 551 551 ctx neighborhood:548
Rv1234 transmembrane protein 500 482 ctx neighborhood:480
Rv1238 sugC sugar ABC transporter ATP-binding protein SugC 433 411 ctx neighborhood:404
Rv1235 lpqY trehalose ABC transporter substrate-binding lipoprotein LpqY 412 411 ctx neighborhood:404
Rv1237 sugB sugar ABC transporter permease SugB 408 408 ctx neighborhood:404
Rv1236 sugA sugar ABC transporter permease SugA 429 407 ctx neighborhood:404
Rv1239c corA magnesium and cobalt transport transmembrane protein CorA 436 207

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: magnesium transporter
  • Pfam (hmmscan --cut_ga): SH3_actinomycetes PF26205.1 (E=3e-22), MgtE_N PF03448.23 (E=9e-23), CBS PF00571.34 (E=8e-08)
  • (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_215748.1)
  • Domains: Pfam-A via hmmscan --cut_ga — SH3_actinomycetes (PF26205.1), MgtE_N (PF03448.23), CBS (PF00571.34)
  • 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 COG2239
  • Curated reference: UniProt O86315 (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 87.4)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 10 functional partner(s); context anchor Rv1231c
  • 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)
  • 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_001321|Rv1232c|
MGSVNRVYLARLSRMSVLGPLGESFGRVRDVVISISIVRQQPRVLGLVVDLATRRKIFIPILRVAAIEPHAVTLSTGNVSLHRFEQRPGEALALGQVLDTLVKVNDPALPELAGVDVVVTDLGVEQTRSRDWMVTRVAVRTQRRLRRRGPVHVVDWHNVAGLTPSALAMPGQDVAQLLDQFEGWKAVDVADAIRGLPPKRRHEVFKALHDKRLADVLQELPELDQAEVLSQLGTERAADVLEEMDPDDAADLLAVLNPTEAELLLTRMDPGDSGQVRRLLTHSPDTAGGLMTSDPVVLTPDTSIAEALARVRDPDLTPALASMVFVARPPTATPTGHYLGCVHLQRLLRDPPAELVGGVVDTDLLTLTPETPLAAVTRYFAAYNLVCGPVVDDENHLLGAVTVDDLLDHLLPHDWRVDMPELDPSGAPDRPGGPR