Rv0157A Still unknown · low auto-curated

H37Rv Rv0157A · MTBC0 - · 42 aa · 186495–186623 H37Rv (-) · RefSeq YP_007408797.1

Genomic neighbourhood (genome browser)

Open in full genome browser →

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-annotation
Revised (this work)Conserved hypothetical protein; no recognised domain. Function unknown. Foldseek best (non-significant) hit: 8w9z-assembly1_F The cryo-EM structure of the Nicotiana tabacum PEP-PA (prob 0.09, TM 0.77).
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.

Annotated on the H37Rv protein: this gene has no 1:1 ancestral MTBC0 anchor (PE/PPE, paralogue, IS element, or otherwise unanchored CDS).

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) highly disordered

Predicted disorder76% of residues (metapredict) · mean AlphaFold pLDDT 70.5
Disordered regions1 IDR(s), longest 42 aa [0-42]

sequence-based disorder is high but AlphaFold folds it confidently (pLDDT>=70): treat the disorder call with caution (possible metapredict over-call)

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).

Binding-pocket screen (P2Rank, geometric prediction) detector blind at this length

Pockets found0
Model length screened42 aa

Read with care. This protein (42 aa) is below the size where this detector has meaningful power: on proven enzymes, only 3.8% (1/26) under 200 aa reach the P2Rank confidence threshold, versus 60.5% (75/124) above it (P16.3b calibration, negative control EsxA/EsxB-scale panel). A negative or weak pocket result here should NOT be read as evidence against a ligand-binding role -- the test essentially has no power at this length, not that the protein lacks a site. P16.3e, calibration phase72b_pocket_calibration.py, 2026-08-03.

CRISPRi vulnerability

Vulnerability index 0.17 (95% CI -1.18 to 2.39). 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 Mb0162A · 97.6% identity
M. marinum MMAR_0380 · 87.8% identity
M. orygis RJtmp_000171 · 97.6% 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 I6WXK8 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 S Function unknown
eggNOG descriptionCysteine-rich secretory protein family
Orthologous groupCOG2340

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.

Outgroup conservation (beyond the MTBC) Mycobacterium

Genus-wide presence (~53 non-MTBC Mycobacterium) present in 53/53 (100%) · mean identity 81.1% · 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

short ORF (42 aa) a shallow stratum may reflect homology-detection failure, not true youth
present across the genus Mycobacterium (NTM) but not detected in any non-Mycobacterium genome — a Mycobacterium-genus 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) 5 in the ORF — 0 in the essential state, 0 growth-defect, 5 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 104. 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 5 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 5 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 6 of 16 independent MS datasets
Integrated abundance51.0 ppm · rank 1735/3519 (50.7th 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)

Length42 aa
Molecular weight4.8 kDa
Theoretical pI4.05
GRAVY-0.481 (hydrophilic)
Aliphatic index51.0
Aromaticity0.19
Instability index62.5 (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 neighbours (Foldseek on the ESMFold model, exploratory)

ESMFold model confidence: mean pLDDT 60.6 (low). Low-confidence model: the fold may be unreliable, so treat these structural hits with caution.

Best matches against the PDB, ranked by Foldseek homology probability. A high probability / TM-score suggests a shared fold; unless flagged sig (E < 0.01) these are fold hypotheses, not assignments.

TargetProbTME-valueDescription
8w9z-assembly1_F 0.09 0.77 9.9e+00 8w9z-assembly1_F The cryo-EM structure of the Nicotiana tabacum PEP-PAP

Genomic context (neighbours & predicted operon)

Upstream (5' on genome)pntB (+ strand, 15 bp gap)
Downstream (3' on genome)Rv0158 (+ strand, 161 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: Rv0158 (transcriptional regulator), medium confidence from genomic context alone (score 558 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv0158 transcriptional regulator 558 558 ctx neighborhood:558
Rv1200 exp integral membrane transport protein 548 541 database:487
Rv1972 Mce associated membrane protein 483 459
Rv1950c hyp hypothetical protein 441 441 coexpression:431
Rv0756c hyp hypothetical protein 439 440 coexpression:430
Rv3881c espB ESX-1 secretion-associated protein EspB 438 439 coexpression:429
Rv0909 antitoxin 438 438 coexpression:428
Rv3903c cpnT hyp hypothetical protein 438 438 coexpression:428
Rv1305 atpE exp ATP synthase subunit C 430 430 database:418
Rv1362c membrane protein 435 410
Rv1973 Mce associated membrane protein 435 410
Rv3492c Mce associated protein 418 392
Rv1363c membrane protein 417 391
Rv2390c hyp hypothetical protein 416 390
Rv0200 transmembrane protein 416 390

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

  • Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): hypothetical protein
  • Foldseek best: 8w9z-assembly1_F The cryo-EM structure of the Nicotiana tabacum PEP-PAP (prob 0.09, E=1e+01, TM=0.77)
  • (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 YP_007408797.1)
  • 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 COG2340
  • Curated reference: UniProt I6WXK8 (TrEMBL, unreviewed; Evidence at protein level)
  • Model confidence: ESMFold per-residue pLDDT (mean 60.6, low)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 19 functional partner(s); context anchor Rv0158
  • 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

>H37Rv|Rv0157A|
MMDPSPDYDVSDEIEFFFRYLTWGLRGVETGDGYPPPAYPPV