rpfE Resolved · high auto-curated
H37Rv Rv2450c · MTBC0 mtbc0_002609 ·
172 aa ·
2775910–2776428 MTBC0
(-) ·
RefSeq NP_216966.1
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) | resuscitation-promoting factor RpfE |
|---|---|
| MTBC0 PGAP re-annotation | resuscitation-promoting factor protein RpfE |
| Revised (this work) | Resuscitation-promoting factor protein RpfE. Pfam: Transglycosylas (PF06737.20). |
| Functional category (TubercuList) | cell wall and cell processes |
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) 35 publications
35 TB publications mention this gene. 35 publication(s) discuss this gene (35 in a M. tuberculosis context, 5 in other mycobacteria — M. smegmatis (3), M. marinum (2)).
| Publication | Date |
|---|---|
| Enhanced immunogenicity in mouse by recombinant BCG prime and protein boost based on latency antigen Rv1733c and/or reactivation antigen RpfE. doi:10.1186/s12879-025-11534-w | 2025 |
| Immunoinformatics design and experimental expression of a multi-epitope vaccine simultaneously targeting AAV2 and HAdV-F41 against acute hepatitis of unknown etiology. doi:10.1016/j.virol.2025.110653 | 2025 |
| Immunoinformatic development of a multiepitope messenger RNA vaccine targeting lipoate protein ligase and dihydrolipoamide dehydrogenase proteins of Mycoplasma bovis in cattle. doi:10.14202/vetworld.2025.1675-1684 | 2025 |
| Multiepitope mRNA Vaccine mRNA-mEp21-FL-IDT Provides Efficient Protection against M. tuberculosis. doi:10.1134/S0006297925600073 | 2025 |
| Discovery of novel vaccine candidates based on the immunogenic epitopes derived from Toxoplasma membrane proteins. doi:10.7774/cevr.2025.14.e4 | 2025 |
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.
Intrinsic disorder (sequence + structure) highly disordered
| Predicted disorder | 52% of residues (metapredict) · mean AlphaFold pLDDT 74.7 |
|---|---|
| Disordered regions | 1 IDR(s), longest 89 aa [0-89] |
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).
Conditional expression context (iModulons)
Member of 1 independently-modulated gene set(s):
Fumarate Reductase.
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 -0.12 (95% CI -1.15 to 1.14). 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 function | Thought to promote the resuscitation and growth of dormant, nongrowing cells. Could also stimulate the growth of several other high G+C gram+ organisms, e.g. Mycobacterium avium, Mycobacterium bovis (BCG), Mycobacterium kansasii, Mycobacterium smegmatis. |
|---|
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 |
Mb2477c
· 98.8% identity |
|---|---|
| M. marinum |
MMAR_3776
· 87.3% identity |
| M. smegmatis |
MSMEG_4643
· 79.2% identity |
| M. orygis |
RJtmp_002533
· 98.8% identity |
| M. abscessus |
MAB_1597
· 85.1% 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 |
O53177
SwissProt · reviewed
· Evidence at protein level
|
|---|---|
| UniProt name | Resuscitation-promoting factor RpfE |
| EC (curated) |
EC 3.-.-.-
|
| Curated function | Factor that stimulates resuscitation of dormant cells. Has peptidoglycan (PG) hydrolytic activity. Active in the pM concentration range. Has little to no effect on actively-growing cells. PG fragments could either directly activate the resuscitation pathway of dormant bacteria or serve as a substrate for endogenous Rpf, resulting in low molecular weight products with resuscitation activity..; FUNCTION: Stimulates growth of stationary phase M.bovis (a slow-growing Mycobacterium), reduces the lag phase of diluted fast-growers M.smegmatis and Micrococcus luteus. Sequential gene disruption indicat. |
Functional vocabulary (eggNOG-mapper, orthology transfer)
| COG category |
M Cell wall / membrane / envelope biogenesis
|
|---|---|
| Preferred name | rpfE |
| eggNOG description | Transglycosylase-like domain |
| Orthologous group | COG1388 |
| KEGG orthology |
K21687, K21691
|
| CAZy family |
GH23
|
| Gene Ontology (20) |
GO:0005575, GO:0005576, GO:0008150, GO:0009892, GO:0009893, GO:0010468, GO:0010604, GO:0010605, GO:0010628, GO:0010629, GO:0019222, GO:0040008 +8 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 | 1.083 · relaxed/neutral |
|---|---|
| Polymorphic sites (≥ 0.1% of strains) | 2 synonymous, 6 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) Mycobacterium
| M. canettii dN/dS (deep-divergence selection) |
0.181 (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 5/53 (9%) · mean identity 64.3%
· 1/4 closest MTBAP relatives present in a subset of the genus (5/53 NTM; in 1 of the 4 closest MTBAP relatives) — partial/intermediate conservation |
| Phylostratum (deepest detected homolog) |
MTBC-specific → Mycobacterium → Mycobacteriaceae → Corynebacteriales → Actinomycetia → Bacteria 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 call | NE · non-essential |
|---|---|
| What the call means | non-essential |
| TA sites (Himar1) | 8 in the ORF — 0 in the essential state, 0 growth-defect, 8 non-essential, 0 growth-advantage. Saturation 0.875, mean read count 74.2857142857. A region of the protein devoid of TA sites is invisible to this assay: nothing can be inferred about it, in either direction. |
| Caveat | Read with some caution: only 8 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 8 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.
Mutant phenotypes (conditional Tn-seq, MtbTnDB) in-vivo phenotype
| Condition | log2FC | q | Effect |
|---|---|---|---|
| fitness in mouse infection (in vivo) | -1.10 | 0.0042 | required |
Conditional fitness of transposon-disruption mutants across 1 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 detection | detected in 5 of 16 independent MS datasets |
|---|---|
| Integrated abundance | 1.47 ppm · rank 3221/3519 (8.5th 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) signal peptide
| Prediction | predicted secreted protein (signal peptide) |
|---|---|
| DeepTMHMM class | SP |
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)
| Length | 172 aa |
|---|---|
| Molecular weight | 17.4 kDa |
| Theoretical pI | 4.22 |
| GRAVY | -0.263 (hydrophilic) |
| Aliphatic index | 69.5 |
| Aromaticity | 0.064 |
| Instability index | 48.2 (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)
| Pfam | Accession | i-Evalue | Residues | Description |
|---|---|---|---|---|
Transglycosylas | PF06737.20 | 1.1e-34 | 96–168 | Transglycosylase-like domain |
Experimental structures (Protein Data Bank) 1 solved
| PDB | Method | Resolution | Coverage |
|---|---|---|---|
4cge |
X-ray diffraction | 2.756 Å | 52% |
Experimentally solved structures mapped from the UniProt accession via PDBe/SIFTS (1 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 74.7
| PDB hit | prob | TM-score | E-value | Description |
|---|---|---|---|---|
4cge-assembly1_A |
1.00 | 0.99 | 3.0e-12 sig | 4cge-assembly1_A Crystal structure of Mycobacterium tuberculosis Resuscitation promoting factor E |
4cge-assembly2_B |
1.00 | 0.98 | 9.1e-11 sig | 4cge-assembly2_B Crystal structure of Mycobacterium tuberculosis Resuscitation promoting factor E |
4cge-assembly6_F |
1.00 | 0.95 | 7.1e-11 sig | 4cge-assembly6_F Crystal structure of Mycobacterium tuberculosis Resuscitation promoting factor E |
4ow1-assembly2_B |
1.00 | 0.99 | 2.1e-09 sig | 4ow1-assembly2_B Crystal Structure of Resuscitation Promoting Factor C |
4ow1-assembly1_A |
1.00 | 0.97 | 3.7e-09 sig | 4ow1-assembly1_A Crystal Structure of Resuscitation Promoting Factor C |
Foldseek search of the AlphaFold DB model (mean pLDDT 74.7, 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) | Rv2449c (- strand, 89 bp gap) |
|---|---|
| Downstream (3' on genome) | Rv2451 (+ strand, 81 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: Rv2449c (trans-acting enoyl reductase), medium confidence from genomic context alone (score 659 excluding text-mining).
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv1954A exp |
Rv1954A, len: 100 aa. Hypothetical unknown protein. | 881 | 881 | coexpression:490 experimental:769 |
Rv2449c |
trans-acting enoyl reductase | 659 | 659 ctx | neighborhood:596 |
Rv2451 hyp |
hypothetical protein | 564 | 563 ctx | neighborhood:559 |
Rv0007 |
membrane protein | 498 | 498 | coexpression:498 |
Rv3268 hyp |
hypothetical protein | 468 | 468 ctx | cooccurence:468 |
Rv2286c hyp |
hypothetical protein | 444 | 444 ctx | cooccurence:444 |
Rv0925c hyp |
hypothetical protein | 466 | 441 | coexpression:440 |
Rv3669 |
transmembrane protein | 440 | 440 | |
Rv2771c hyp |
hypothetical protein | 464 | 439 | coexpression:438 |
Rv2448c valS |
valine--tRNA ligase | 438 | 438 ctx | neighborhood:429 |
Rv2466c hyp |
hypothetical protein | 431 | 431 ctx | cooccurence:429 |
Rv2006 otsB1 |
trehalose-6-phosphate phosphatase OtsB | 460 | 427 | coexpression:417 |
Rv3372 otsB2 |
trehalose 6-phosphate phosphatase | 459 | 426 | coexpression:418 |
Rv2447c folC |
folylpolyglutamate synthase FolC | 420 | 420 ctx | neighborhood:416 |
Rv2446c |
integral membrane protein | 419 | 419 ctx | neighborhood:416 |
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: resuscitation-promoting factor RpfE
- MTBC0 PGAP product: resuscitation-promoting factor protein RpfE
- Pfam (hmmscan --cut_ga): Transglycosylas PF06737.20 (E=1e-34)
- (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_216966.1)
- Domains: Pfam-A via hmmscan --cut_ga — Transglycosylas (PF06737.20)
- 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
COG1388 - Curated reference: UniProt O53177 (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 74.7)
- Interaction network: STRING v12.0 (Szklarczyk et al. 2023,
doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 —
26 functional partner(s); context anchor
Rv2449c - 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
- 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)
- 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_002609|Rv2450c|rpfE MKNARTTLIAAAIAGTLVTTSPAGIANADDAGLDPNAAAGPDAVGFDPNLPPAPDAAPVDTPPAPEDAGFDPNLPPPLAPDFLSPPAEEAPPVPVAYSVNWDAIAQCESGGNWSINTGNGYYGGLQFTAGTWRANGGSGSAANASREEQIRVAENVLRSQGIRAWPVCGRRG
Spot an error? Suggest an improvement
Found a mistake, a missing reference, or have a better functional hypothesis for rpfE? Email the maintainer — the message is pre-filled with this gene's details.