Rv0249c Family assigned · low auto-curated

H37Rv Rv0249c · MTBC0 mtbc0_000265 · 273 aa · 301216–302037 MTBC0 (-) · RefSeq NP_214763.1

Genomic neighbourhood (genome browser)

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+ strand − strand vapB24 (Rv0239) — requalified: antitoxin vapC24 (Rv0240) — family_assigned: type II toxin-antitoxin system VapC family toxin htdX (Rv0241c) — requalified: 3-hydroxyacyl-thioester dehydratase HtdX htdX fabG4 (Rv0242c) — requalified: 3-oxoacyl-ACP reductase fabG4 fadA2 (Rv0243) — requalified: acetyl-CoA C-acetyltransferase fadA2 fadE5 (Rv0244c) — requalified: acyl-CoA dehydrogenase fadE5 Rv0245 (Rv0245) — family_assigned: flavin reductase family protein Rv0246 (Rv0246) — family_assigned: integral membrane protein Rv0246 Rv0247c (Rv0247c) — family_assigned: succinate dehydrogenase/fumarate reductase iron-sulfur subun Rv0248c (Rv0248c) — family_assigned: fumarate reductase/succinate dehydrogenase flavoprotein subu Rv0248c Rv0249c (Rv0249c) — family_assigned: succinate dehydrogenase membrane anchor subunit Rv0250c (Rv0250c) — family_assigned: hypothetical protein hsp (Rv0251c) — requalified: stress-responsive chaperone Acr2 nirB (Rv0252) — family_assigned: nitrite reductase large subunit NirB nirB nirD (Rv0253) — family_assigned: nitrite reductase small subunit NirD cobU (Rv0254c) — requalified: bifunctional adenosylcobinamide kinase/adenosylcobinamide-ph Rv0258c (Rv0258c) — requalified: hypothetical protein Rv0259c (Rv0259c) — family_assigned: sirohydrochlorin chelatase Rv0260c (Rv0260c) — requalified: uroporphyrinogen-III synthase Rv0260c narK3 (Rv0261c) — requalified: nitrate/nitrite transporter 292 kb 296 kb 300 kb 304 kb 308 kb 312 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)succinate dehydrogenase membrane anchor subunit
MTBC0 PGAP re-annotationsuccinate dehydrogenase membrane anchor subunit
Revised (this work)Succinate dehydrogenase membrane anchor subunit.
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) 1 publication

1 TB publication mentions this gene. 1 publication(s) discuss this gene (1 in a M. tuberculosis context).

PublicationDate
Role of intragenic binding of cAMP responsive protein (CRP) in regulation of the succinate dehydrogenase genes Rv0249c-Rv0247c in TB complex mycobacteria. doi:10.1093/nar/gkv420 2015

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 1.91 (95% CI -0.12 to 5.26). 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 functionCould be involved in interconversion of fumarate and succinate (aerobic respiration). This hydrophobic component may be required to anchor the catalytic components of the succinate dehydrogenase complex to the cytoplasmic 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 Mb0255c · 100.0% identity
M. marinum MMAR_0512 · 88.6% identity
M. smegmatis MSMEG_0419 · 80.6% identity
M. orygis RJtmp_000265 · 100.0% identity
M. abscessus MAB_4421 · 77.1% 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 O53671 TrEMBL · unreviewed · Evidence at protein level
UniProt nameProbable succinate dehydrogenase [membrane anchor subunit]

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
eggNOG descriptionmembrane
Orthologous group2CEY7

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 0.193 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 5 synonymous, 3 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 53/53 (100%) · mean identity 75.4% · 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 4/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 68.9%
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) 23 in the ORF — 0 in the essential state, 0 growth-defect, 23 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 47.7826086957. 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) in-vivo phenotype

Conditionlog2FCqEffect
altered fitness under Isoniazid (drug exposure) +4.830.0 disruption advantageous
fitness in mouse infection, day 45 (in vivo) -4.280.0 required
fitness in mouse infection (in vivo) -3.970.0089 required
fitness in mouse infection (in vivo) -3.900.0 required
fitness in mouse infection (in vivo) -3.740.0 required
fitness in mouse infection (in vivo) -3.600.0 required
fitness in mouse infection (in vivo) -3.280.0 required
altered fitness under Isoniazid (drug exposure) +3.210.0 disruption advantageous
fitness in mouse infection (in vivo) -3.070.0065 required
fitness in mouse infection (in vivo) -3.050.0 required
fitness in mouse infection (in vivo) -3.020.0 required
altered fitness under 6 weeks hypoxia (stress) -2.650.0 required

Conditional fitness of transposon-disruption mutants across 45 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 11 of 16 independent MS datasets
Integrated abundance219.0 ppm · rank 800/3519 (77.3th 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.

Predicted localisation (DeepTMHMM + lipobox)

Predictionpredicted membrane protein (5 TM helixes)
DeepTMHMM classTM
TM helices (DeepTMHMM)5

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)

Length273 aa
Molecular weight31.1 kDa
Theoretical pI9.61
GRAVY0.229 (hydrophobic)
Aliphatic index90.4
Aromaticity0.165
Instability index41.4 (unstable)

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)

No Pfam-A domain above the gathering threshold (or not yet scanned).

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 90.6

PDB hitprobTM-scoreE-valueDescription
7d6x-assembly1_C 1.00 0.96 6.2e-30 sig 7d6x-assembly1_C Mycobacterium smegmatis Sdh1 complex in the apo form

Foldseek search of the AlphaFold DB model (mean pLDDT 90.6, 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) operon of 3

Upstream (5' on genome)Rv0248c (- strand, 30 bp gap)
Downstream (3' on genome)Rv0250c (- strand, 79 bp gap)
Predicted operon Rv0247c · Rv0248c · Rv0249c

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: Rv0247c (succinate dehydrogenase iron-sulfur subunit), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0247c exp succinate dehydrogenase iron-sulfur subunit 999 1000 ctx neighborhood:839 cooccurence:774 experimental:997 textmining:870
Rv0248c exp succinate dehydrogenase flavoprotein subunit 998 995 ctx neighborhood:839 cooccurence:771 experimental:870 textmining:655
Rv0250c hyp hypothetical protein 940 879 ctx neighborhood:787 cooccurence:451 textmining:527
Rv3319 sdhB exp succinate dehydrogenase iron-sulphur protein subunit 905 801 experimental:784 textmining:543
Rv1553 frdB exp fumarate reductase iron-sulfur subunit 898 800 experimental:784 textmining:511
Rv3318 sdhA exp succinate dehydrogenase flavoprotein subunit 657 512 experimental:469
Rv1552 frdA exp fumarate reductase flavoprotein subunit 634 509 experimental:469
Rv3687c rsfB anti-anti-sigma factor RsfB 478 478 ctx cooccurence:476
Rv3537 kstD 3-oxosteroid 1-dehydrogenase 409 410
Rv1817 flavoprotein 409 410
Rv3818 hyp hypothetical protein 401 402
Rv0251c hsp heat shock protein 531 399
Rv3316 sdhC succinate dehydrogenase cytochrome B-556 subunit 805 53 textmining:803
Rv3317 sdhD succinate dehydrogenase hydrophobic membrane anchor subunit 802 49 textmining:801
Rv0392c ndhA NADH dehydrogenase NdhA 511 41 textmining: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: succinate dehydrogenase membrane anchor subunit
  • MTBC0 PGAP product: succinate dehydrogenase membrane anchor subunit
  • (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_214763.1)
  • Domains: Pfam-A via hmmscan --cut_ga — none above threshold
  • 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 2CEY7
  • Curated reference: UniProt O53671 (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 90.6)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 15 functional partner(s); context anchor Rv0247c
  • 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
  • Predicted localisation: DeepTMHMM (Hallgren et al. 2022, doi:10.1101/2022.04.08.487609) for transmembrane topology and signal peptide
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000265|Rv0249c|
MSAPTANRPAIGVFTPTRAQIPERTLRTDLWWLPPLLTNLGLLAFICYATTRAFWGSQYWVEKYHYLTPFYSPCVSASCQPGASHLGVWFGHFPGWIPLGAMVLPFLLGFRLTCYYYRKAYYRSVWQSPTSCAVPEPRAHYTGETRLPLIVQNTHRYFFYIAVVVSLINTYDAIAAFHSPSGFGFGLGNVILTINVVLLWAYTISCHSCRHATGGRLKHFSKHPVRYWIWTQVSKLNTRHMQFAWITLGTLALTDFYIMLVASGSITDLRFIG