Rv0312 Family assigned · medium auto-curated

H37Rv Rv0312 · MTBC0 mtbc0_000332 · 620 aa · 383879–385741 MTBC0 (+) · RefSeq NP_214826.1

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)hypothetical protein
MTBC0 PGAP re-annotationHsp70 family protein
Revised (this work)Hsp70 family protein. Pfam: HSP70 (PF00012.27).
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.

Intrinsic disorder (sequence + structure) partially disordered

Predicted disorder25% of residues (metapredict) · mean AlphaFold pLDDT 72.9
Disordered regions1 IDR(s), longest 154 aa [466-620]

carries a substantial disordered region (154/620 residues); disorder is a property, not a function

A property (biophysics), not a function. No LLPS/condensate claim is made from disorder alone. Verdict unchanged. Source: metapredict v3 (Emenecker/Holehouse) per-residue disorder + AlphaFold mean pLDDT (annotation_mtbc P16.13).

Conditional expression context (iModulons)

Member of 1 independently-modulated gene set(s): SigH (sigH).

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 0.87 (95% CI -1.04 to 3.99). 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). 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 Mb0320 · 99.0% identity
M. marinum MMAR_0562 · 74.0% identity
M. smegmatis MSMEG_0638 · 44.4% identity
M. orygis RJtmp_000328 · 98.9% 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 O07239 TrEMBL · unreviewed · Evidence at protein level
UniProt nameConserved hypothetical proline and threonine rich protein

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category O Post-translational modification, protein turnover, chaperones
eggNOG descriptionMolecular chaperone
Orthologous groupCOG0443

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 1.105 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 3 synonymous, 9 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) Corynebacteriales

M. canettii dN/dS (deep-divergence selection) 0.369 (low power) · 6 consensus substitution(s)
low power (6 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 67.7% · 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 2/13 non-Mycobacterium reference genomes (down to Corynebacteriales) · mean identity 36.2%
detected across the order Corynebacteriales (Corynebacterium/Nocardia/Rhodococcus/…) but not in more distant Actinomycetia — a Corynebacteriales-level 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) 22 in the ORF — 0 in the essential state, 0 growth-defect, 22 non-essential, 0 growth-advantage. Saturation 0.773, mean read count 50.9411764706. 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 10 of 16 independent MS datasets
Integrated abundance24.3 ppm · rank 2204/3519 (37.4th 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 (1 TM helix)
DeepTMHMM classTM
TM helices (DeepTMHMM)1

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)

Length620 aa
Molecular weight64.1 kDa
Theoretical pI5.09
GRAVY0.039 (hydrophobic)
Aliphatic index87.4
Aromaticity0.044
Instability index50.4 (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)

PfamAccessioni-EvalueResiduesDescription
HSP70PF00012.27 3.0e-17158–347 Hsp70 protein

Structural search (AlphaFold DB model, Foldseek vs PDB — genome-wide) pLDDT 72.9

PDB hitprobTM-scoreE-valueDescription
5obv-assembly1_A 1.00 0.74 7.1e-20 sig 5obv-assembly1_A Mycoplasma genitalium DnaK deletion mutant lacking SBDalpha in complex with ADP and Pi.
6w6e-assembly1_I 1.00 0.76 2.9e-19 sig 6w6e-assembly1_I The Mycobacterium tuberculosis ClpB disaggregase hexamer structure with a locally refined ClpB middle domain and a DnaK nucleotide binding domain
5obu-assembly1_A 1.00 0.73 6.0e-20 sig 5obu-assembly1_A Mycoplasma genitalium DnaK deletion mutant lacking SBDalpha in complex with AMPPNP.
3iuc-assembly3_C 1.00 0.71 6.0e-20 sig 3iuc-assembly3_C Crystal structure of the human 70kDa heat shock protein 5 (BiP/GRP78) ATPase domain in complex with ADP
3qml-assembly1_A 1.00 0.71 1.0e-19 sig 3qml-assembly1_A The structural analysis of Sil1-Bip complex reveals the mechanism for Sil1 to function as a novel nucleotide exchange factor

Foldseek search of the AlphaFold DB model (mean pLDDT 72.9, 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)Rv0311 (+ strand, 154 bp gap)
Downstream (3' on genome)Rv0313 (+ strand, 71 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: pirG (cell surface protein), high confidence from genomic context alone (score 860 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv2299c htpG exp chaperone protein HtpG 977 969 coexpression:668 experimental:772 database:622
Rv0351 grpE exp stress response protein GrpE 961 947 coexpression:704 experimental:773
Rv0352 dnaJ1 exp chaperone protein DnaJ 929 919 coexpression:629 experimental:476 database:601
Rv2373c dnaJ2 exp chaperone protein DnaJ 929 918 coexpression:626 experimental:476 database:601
Rv3810 pirG cell surface protein 865 860 ctx cooccurence:452 coexpression:754
Rv2721c hyp hypothetical protein 851 850 coexpression:827
Rv3417c groEL1 exp chaperonin GroEL 851 828 coexpression:627 experimental:410
Rv0440 groEL2 exp molecular chaperone GroEL 851 827 coexpression:629 experimental:410
Rv0040c mtc28 hyp hypothetical protein 812 812 coexpression:812
Rv3596c clpC1 exp ATP-dependent protease ATP-binding subunit ClpC 832 808 coexpression:614 experimental:508
Rv1469 ctpD cobalt/nickel-exporting P-type ATPase 816 808 coexpression:785
Rv0384c clpB exp chaperone protein ClpB 831 807 coexpression:612 experimental:508
Rv2667 clpC2 exp ATP-dependent protease ATP-binding subunit ClpC 831 807 coexpression:612 experimental:508
Rv0342 iniA exp isoniazid inductible protein IniA 806 795 ctx cooccurence:607 database:411
Rv0888 spmT hyp hypothetical protein 792 788 coexpression:734

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: Hsp70 family protein
  • Pfam (hmmscan --cut_ga): HSP70 PF00012.27 (E=3e-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_214826.1)
  • Domains: Pfam-A via hmmscan --cut_ga — HSP70 (PF00012.27)
  • 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 COG0443
  • Curated reference: UniProt O07239 (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 72.9)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 228 functional partner(s); context anchor pirG
  • 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
  • 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_000332|Rv0312|
MYDPLGLSIGTTNLVAAGNGGPPVTRRAVLTLYPHCAPKIGVPSQNPNLIEPGALMSGFVERIGDAVALVSPDGSVHDPDLLLVEALDAMVLTAGADASSSEIAIAVPAHWKPGAVHALRNGLRTHVGFVRSGMAPRLVSDAIAALTAVNSELGLPHGGVVGLLDFGGSATYVTLVETKSDSRTSDFQPVSATARYQDFSGSQIDQALLLRVIDQFGYGDDVDPASTAAVGQLGQLREQCRAAKERLSTDVATELFAELAGCSSSIEMTREQLEDLIQDPLTGFIYAFDDMLARHNASWADLAAVVTVGGGANIPLVTQRLSFHTRRPVLTASQPGCAAAMGALLLANRGGERDSRTRTSIGLATAAAAGTSVIELPAGDVMVIDHEALTDRELAWSQTDFPSEAPARFEGDSYNEGGPCWSMRLNAVEPPKGPAWRRIRVSQLLIGVSAVVAMTAIGGVALTLTAIERRPSPLPTPIVPGLAPMPPGSVVPSSRAPTPPPPPSTVAPLPSAAPAPTTVAPAPPPPTQVVTTTTAPPVTTTPRPSPTTTTTTAPPSTTTTTEPPVTTTSTIPTIPTTTTTVKMTTEWLHVPFLPVPIPVPIPQNPGAGEPQNPFGSLGSG