Rv1012 Still unknown · low auto-curated

H37Rv Rv1012 · MTBC0 mtbc0_001087 · 49 aa · 1138464–1138758 MTBC0 (+) · RefSeq NP_215528.1

⚠ The ancestral MTBC0 ORF appears truncated by an internal (premature) stop codon: the translated ancestral protein (49 aa) is shorter than its annotated CDS span (≈97 aa / 295 bp). This is expected for degraded mobile elements (phage, IS, transposase); for a conserved gene it more likely reflects a reconstruction artefact in MTBC0 v1.1. Note: the structural and functional layers below were computed on the translated (truncated) sequence.

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationhypothetical protein
Revised (this work)Conserved hypothetical protein; no recognised domain. Function unknown.
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 TB publication mentions this locus tag in its title or abstract (sweep of a ~330k-abstract PubMed TB corpus). This gene is genuinely unstudied: its darkness reflects absence of investigation, not failure of investigation.

An antigen status or a virulence phenotype is NOT a molecular function: the verdict stays unchanged. This layer adds the missing context, it does not requalify the gene. 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 of title+abstract: the 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, 2026-07-13.

Intrinsic disorder (sequence + structure) dark by construction (IDR-orphan)

Predicted disorder100% of residues (metapredict) · mean AlphaFold pLDDT 47.1
Disordered regions1 IDR(s), longest 49 aa [0-49]

both sequence (metapredict) and structure (low AlphaFold pLDDT) indicate little stable globular structure: this gene is dark BY CONSTRUCTION — there is no confident fold for structure/homology search to match, so its obscurity is expected, not a pipeline failure

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).

CRISPRi vulnerability

Vulnerability index 0.60 (95% CI -7.87 to 9.53). 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).

Orthologues (reciprocal best hits across mycobacteria)

M. bovis Mb1040 · 98.4% 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 O05597 TrEMBL · unreviewed · Predicted
UniProt nameUncharacterized protein

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

Conservation & selection (intra-MTBC, 145 209 strains) pseudogene candidate

pN/pS n/a
Polymorphic sites (≥ 0.1% of strains) 0 synonymous, 3 missense, 0 nonsense, 1 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 29.73% of strains (43173) · 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) MTBC-specific

M. canettii dN/dS (deep-divergence selection) inf (low power) · 2 consensus substitution(s) · 1 canettii-fixed disruption
low power (2 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable; carries 1 M. canettii-clade-fixed disruptive substitution(s) (candidate lineage-specific pseudogenisation — cross-check the intra-MTBC pseudogene layer)
Genus-wide presence (~53 non-MTBC Mycobacterium) present in 0/53 (0%) · 0/4 closest MTBAP relatives
absent from ALL 53 non-MTBC Mycobacterium genomes tested (incl. the closest MTBAP relatives) — a candidate MTBC-specific genetic innovation / host-adaptation factor (confirm by synteny; rule out a short/low-complexity ORF and extreme divergence)
Phylostratum (deepest detected homolog) MTBC-specific Mycobacterium Mycobacteriaceae Corynebacteriales Actinomycetia Bacteria

short ORF (49 aa) a shallow stratum may reflect homology-detection failure, not true youth
absent from the whole genus and from all outgroups tested — a candidate MTBC-specific innovation (confirm by synteny; rule out detection failure for short/divergent ORFs)

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) 6 in the ORF — 0 in the essential state, 0 growth-defect, 6 non-essential, 0 growth-advantage. Saturation 0.833, mean read count 129.2. 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 6 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 6 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) detected

MS detectiondetected in 1 of 16 independent MS datasets
Integrated abundance0.01 ppm · rank 3511/3519 (0.3th 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)

Length49 aa
Molecular weight5.3 kDa
Theoretical pI12.0
GRAVY-0.804 (hydrophilic)
Aliphatic index58.2
Aromaticity0.041
Instability index33.9 (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)

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

Genomic context (neighbours & predicted operon) operon of 2

Upstream (5' on genome)ispE (+ strand, 16 bp gap)
Downstream (3' on genome)pks16 (+ strand, 203 bp gap)
Predicted operon ispE · Rv1012

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 (1 TF) whiA (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: ispE (4-diphosphocytidyl-2C-methyl-D-erythritol kinase), high confidence from genomic context alone (score 728 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv1011 ispE 4-diphosphocytidyl-2C-methyl-D-erythritol kinase 728 728 ctx neighborhood:727
Rv1010 ksgA rRNA small subunit methyltransferase A 518 518 ctx neighborhood:515
Rv1009 rpfB resuscitation-promoting factor RpfB 517 517 ctx neighborhood:515
Rv1013 pks16 polyketide synthase 447 447 ctx neighborhood:445

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: hypothetical protein
  • (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_215528.1)
  • Domains: Pfam-A via hmmscan --cut_ga — none above threshold
  • Sequence-level signal: ESM Atlas (EvolutionaryScale × BioHub) — exploratory
  • Curated reference: UniProt O05597 (TrEMBL, unreviewed; Predicted)
  • Intra-MTBC selection: pN/pS and disruption from SPDI variants of 145 209 MTBC strains (this work, local collection vs H37Rv NC_000962.3)
  • Model confidence: ESMFold per-residue pLDDT (mean 46.8, very low)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 4 functional partner(s); context anchor ispE
  • 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)
  • 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
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001087|Rv1012|
MPRAARGIRACRGRWVDRLAHQHASGRAAGIRPRGGRWRASKPGAKAIP