Rv1129c Family assigned · medium auto-curated

H37Rv Rv1129c · MTBC0 mtbc0_001212 · 486 aa · 1261514–1262974 MTBC0 (-) · RefSeq NP_215645.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)transcriptional regulator
MTBC0 PGAP re-annotationshort-chain fatty acyl-CoA regulator family protein
Revised (this work)Short-chain fatty acyl-CoA regulator family protein. Pfam: HTH_31 (PF13560.13), HTH_3 (PF01381.29), Peptidase_M78 (PF06114.20), ScfRs (PF09856.15).
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) 3 publications

3 TB publications mention this gene. 3 publication(s) discuss this gene (3 in a M. tuberculosis context).

PublicationDate
Discrepancies in isoniazid susceptibility profiles: Bactec MGIT 960-resistant but GenoType MTBDRplus-susceptible Mycobacterium tuberculosis strains in Hunan, China. doi:10.1128/spectrum.01101-25 2025
Cholesterol catabolism by Mycobacterium tuberculosis requires transcriptional and metabolic adaptations. doi:10.1016/j.chembiol.2011.12.016 2012
Evidence for complex interactions of stress-associated regulons in an mprAB deletion mutant of Mycobacterium tuberculosis. doi:10.1099/mic.0.29281-0 2007

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): PrpR (prpR).

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 1.44 (95% CI -0.73 to 5.13). 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

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 Mb1160c · 100.0% identity
M. marinum MMAR_1378 · 67.2% identity
M. smegmatis MSMEG_6643 · 68.2% identity
M. orygis RJtmp_001191 · 100.0% identity
M. abscessus MAB_4616c · 66.6% 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 O06581 SwissProt · reviewed · Evidence at protein level
UniProt nameHTH-type transcriptional regulator PrpR
Curated functionPlays a key role in regulating expression of enzymes involved in the catabolism of short chain fatty acids (SCFA) via both the glyoxylate (acetyl degradation route) and the methylcitrate cycle (propionate degradation route). Required for intracellular growth in macrophages and for the assimilation of cholesterol-derived propionate. PrpR acts as a transcriptional activator of prpDC and icl genes when propionate is the main carbon source, and as a ramB repressor. During growth on propionate, PrpR also acts as a transcriptional repressor of dnaA, which encodes the DnaA initiator protein responsib.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category K Transcription
eggNOG descriptionIrrE N-terminal-like domain
Orthologous groupCOG1396
KEGG orthology K07110, K21686
Gene Ontology (56) GO:0001666, GO:0006082, GO:0006355, GO:0006629, GO:0006631, GO:0006950, GO:0008150, GO:0008152, GO:0009605, GO:0009607, GO:0009628, GO:0009889 +44 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 0.847 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 2 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) 0.679 (low power) · 3 consensus substitution(s)
low power (3 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable
Genus-wide presence (~53 non-MTBC Mycobacterium) present in 51/53 (96%) · mean identity 64.8% · 4/4 closest MTBAP relatives
conserved across the genus (present in 51/53 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 8/13 non-Mycobacterium reference genomes (down to Actinomycetia) · mean identity 51.7%
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) cholesterol-required

DeJesus 2017 callNE · non-essential
What the call meansnon-essential
TA sites (Himar1) 27 in the ORF — 0 in the essential state, 0 growth-defect, 27 non-essential, 0 growth-advantage. Saturation 0.852, mean read count 28.4347826087. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction.
Cholesterol catabolismrequired for growth on cholesterol (Griffin 2011)

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.

Conditional fitness (RB-TnSeq, 95 conditions) carbon source

ConditionGroupDirectionlog2 fitnesst
heptadecanoic acid carbon source mutant depleted (gene required) -2.253 -9.809
Sodium propionate carbon source mutant depleted (gene required) -4.588 -9.747
Valeric acid carbon source mutant depleted (gene required) -4.393 -9.354

Randomly-barcoded transposon screen across 95 carbon/nitrogen sources, pH, stressors and antibiotics (3 condition-specific phenotype(s) for this gene). A conditional fitness phenotype is a context lead, not a proven function, and never changes the verdict here. Note the blind spot: RB-TnSeq cannot measure essential genes. Source: RB-TnSeq 95-condition barcoded transposon screen, Mtb (PLoS Biol 2026, doi:10.1371/journal.pbio.3003529).

Mutant phenotypes (conditional Tn-seq, MtbTnDB) in-vivo phenotype

Conditionlog2FCqEffect
fitness on cholesterol (vs glycerol) (carbon source) -5.530.0 required
fitness in mouse infection (in vivo) -1.290.0 required

Conditional fitness of transposon-disruption mutants across 2 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 9 of 16 independent MS datasets
Integrated abundance7.93 ppm · rank 2770/3519 (21.3th 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)

Length486 aa
Molecular weight54.1 kDa
Theoretical pI7.71
GRAVY-0.216 (hydrophilic)
Aliphatic index85.7
Aromaticity0.086
Instability index46.3 (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)

PfamAccessioni-EvalueResiduesDescription
HTH_31PF13560.13 1.1e-1019–72 Helix-turn-helix domain
HTH_3PF01381.29 1.3e-1222–76 Helix-turn-helix
Peptidase_M78PF06114.20 7.9e-26200–322 IrrE N-terminal-like domain
ScfRsPF09856.15 7.4e-66323–479 Short-chain fatty acyl coenzyme A regulator, C-terminal

Experimental structures (Protein Data Bank) 4 solved

PDBMethodResolutionCoverage
6cyy X-ray diffraction 2.506 Å 83%
6cyj X-ray diffraction 2.699 Å 83%
6cz6 X-ray diffraction 2.7 Å 83%
6d2s X-ray diffraction 1.819 Å 59%

Experimentally solved structures mapped from the UniProt accession via PDBe/SIFTS (4 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 87.4

PDB hitprobTM-scoreE-valueDescription
6cyj-assembly1_B 1.00 1.00 1.3e-55 sig 6cyj-assembly1_B Mycobacterium tuberculosis transcriptional regulator
6cyy-assembly1_A 1.00 1.00 3.4e-55 sig 6cyy-assembly1_A Mycobacterium tuberculosis transcriptional regulator
6cz6-assembly1_B 1.00 1.00 7.7e-55 sig 6cz6-assembly1_B Mycobacterium tuberculosis transcriptional regulator
6cz6-assembly1_C 1.00 1.00 2.9e-54 sig 6cz6-assembly1_C Mycobacterium tuberculosis transcriptional regulator
6cz6-assembly1_D 1.00 1.00 5.0e-54 sig 6cz6-assembly1_D Mycobacterium tuberculosis transcriptional regulator

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)

Upstream (5' on genome)Rv1128c (- strand, 101 bp gap)
Downstream (3' on genome)prpD (+ strand, 20 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 (5 TF) Rv0081 (activates) · mmpR5 (activates) · Rv2887 (represses) · devR (activates) · Rv3249c (represses)

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: prpD (2-methylcitrate dehydratase), high confidence from genomic context alone (score 884 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1130 prpD 2-methylcitrate dehydratase 991 884 ctx neighborhood:621 cooccurence:519 coexpression:415 textmining:928
Rv1131 prpC methylcitrate synthase PrpC 961 804 ctx neighborhood:597 coexpression:533 textmining:810
Rv1132 hyp hypothetical protein 606 606 ctx neighborhood:553
Rv1128c hyp hypothetical protein 549 546 ctx neighborhood:534
Rv0332 hyp exp hypothetical protein 506 479 experimental:434
Rv0366c hyp exp hypothetical protein 473 445 experimental:434
Rv0467 icl1 isocitrate lyase 755 394 textmining:613
Rv1493 mutB methylmalonyl-CoA mutase large subunit 413 242
Rv3833 AraC family transcriptional regulator 455 210

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
  • MTBC0 PGAP product: short-chain fatty acyl-CoA regulator family protein
  • Pfam (hmmscan --cut_ga): HTH_31 PF13560.13 (E=1e-10), HTH_3 PF01381.29 (E=1e-12), Peptidase_M78 PF06114.20 (E=8e-26), ScfRs PF09856.15 (E=7e-66)
  • (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_215645.1)
  • Domains: Pfam-A via hmmscan --cut_ga — HTH_31 (PF13560.13), HTH_3 (PF01381.29), Peptidase_M78 (PF06114.20), ScfRs (PF09856.15)
  • 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 COG1396
  • Curated reference: UniProt O06581 (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 87.4)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 9 functional partner(s); context anchor prpD
  • Essentiality: genome-wide transposon mutagenesis in H37Rv — DeJesus et al. 2017 (mBio, doi:10.1128/mBio.02133-16, CC BY); cholesterol requirement from Griffin et al. 2011 (doi:10.1371/journal.ppat.1002251)
  • 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)
  • 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)
  • 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_001212|Rv1129c|
MTRSNVLPVARTYSRTFSGARLRRLRQERGLTQVALAKALDLSTSYVNQLENDQRPITVPVLLLLTERFDLSAQYFSSDSDARLVADLSDVFTDIGVEHAVSGAQIEEFVARMPEVGHSLVAVHRRLRAATEELEGYRSRATAETELPPARPMPFEEVRDFFYDRNNYIHDLDMAAERMFTESGMRTGGLDIQLAELMRDRFGISVVIDDNLPDTAKRRYHPDTKVLRVAHWLMPGQRAFQIATQLALVGQSDLISSIVATDDQLSTEARGVARIGLANYFAGAFLLPYREFHRAAEQLRYDIDLLGRRFGVGFETVCHRLSTLQRPRQRGIPFIFVRTDKAGNISKRQSATAFHFSRVGGSCPLWVVHDAFAQPERIVRQVAQMPDGRSYFWVAKTTAADGLGYLGPHKNFAVGLGCDLAHAHKLVYSTGVVLDDPSTEVPIGAGCKICNRTSCAQRAFPYLGGRVAVDENAGSSLPYSSTEQSV