groEL1 Resolved · high auto-curated

H37Rv Rv3417c · MTBC0 mtbc0_003631 · 539 aa · 3860711–3862330 MTBC0 (-) · RefSeq NP_217934.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)chaperonin GroEL
MTBC0 PGAP re-annotationchaperonin GroEL
Revised (this work)Chaperonin GroEL. Pfam: Cpn60_TCP1 (PF00118.30).
Functional category (TubercuList)virulence, detoxification, adaptation

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) 44 publications

44 TB publications mention this gene. 44 publication(s) discuss this gene (32 in a M. tuberculosis context, 15 in other mycobacteria — M. smegmatis (10), M. abscessus (3), M. leprae (2), M. marinum (1)).

Most recent 5 of 44.
PublicationDate
New moonlighting activities for various GroEL/Hsp60 proteins, mainly characterized using recombinant M. tuberculosis GroEL1. doi:10.1016/j.ijbiomac.2025.149266 2026
Proteomic Analysis of Drug-Resistant Mycobacterium tuberculosis Clinical Isolates Under Aminoglycoside Drug Pressure. doi:10.1007/s00284-025-04341-8 2025
Mycobacterial Biofilm: Mechanisms, Clinical Problems, and Treatments. doi:10.3390/ijms25147771 2024
Analysis of the components of Mycobacterium tuberculosis heat-resistant antigen (Mtb-HAg) and its regulation of γδ T-cell function. doi:10.1186/s11658-024-00585-7 2024
Beyond copper: examining the significance of His-mutations in mycobacterial GroEL1 HRCT for Ni(II) complex stability and formation. doi:10.1039/d4dt00011k 2024

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): GroEL-GroES Complex.

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).

Post-translational modifications

4 reported modified residue(s), incl. 3 phosphosite(s): N-acetylserine @2, Phosphothreonine @25, Phosphothreonine @54, Phosphoserine; in tetradecamer @393.

Experimentally reported post-translational modification(s). A phosphosite indicates the protein is expressed and is a substrate of the M. tuberculosis Ser/Thr/Tyr kinase signalling network — a regulatory context, NOT a molecular function. Source: UniProt (Modified residue features; PTM sites curated from the M. tuberculosis literature).

CRISPRi vulnerability

Vulnerability index 1.46 (95% CI -0.28 to 4.25). 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 functionPrevents misfolding and promotes the refolding and proper assembly of unfolded polypeptides generated under stress conditions.

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 Mb3451c · 100.0% identity
M. leprae ML0381 · 82.9% identity
M. marinum MMAR_1126 · 87.4% identity
M. smegmatis MSMEG_1583 · 81.9% identity
M. orygis RJtmp_003519 · 100.0% identity
M. abscessus MAB_3731c · 78.0% 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 P9WPE9 SwissProt · reviewed · Evidence at protein level
UniProt nameChaperonin GroEL 1
EC (curated) EC 5.6.1.7
Curated functionPrevents aggregation of substrate proteins and promotes their refolding. In vitro, activity may be independent of the presence or absence of the GroES co-chaperonin or ATP. Shows weak ATPase activity..; FUNCTION: Involved in copper homeostasis. Binds copper and may help maintaining copper homeostasis when copper is present in excess, notably in the macrophage phagosome, by acting as a metal storage protein. Could be involved in copper resistance during mycobacterial biofilm formation. Protects from copper stress in vitro. Can also bind other metals, but binds copper with relatively higher affi.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category O Post-translational modification, protein turnover, chaperones
Preferred namegroL2
eggNOG descriptionPrevents misfolding and promotes the refolding and proper assembly of unfolded polypeptides generated under stress conditions
Orthologous groupCOG0459
KEGG orthology K04077
KEGG pathways map03018, map04212, map04940, map05134, map05152
Gene Ontology (80) GO:0003674, GO:0003676, GO:0003677, GO:0003697, GO:0005488, GO:0005515, GO:0005575, GO:0005618, GO:0005622, GO:0005623, GO:0005737, GO:0005829 +68 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 0.439 · purifying
Polymorphic sites (≥ 0.1% of strains) 4 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) Bacteria

M. canettii dN/dS (deep-divergence selection) 0.0 (low power) · 2 consensus substitution(s)
low power (2 canettii-consensus substitution(s)); present in M. canettii but dN/dS not reliable
Genus-wide presence (~53 non-MTBC Mycobacterium) present in 53/53 (100%) · mean identity 85.8% · 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
detected in 13/13 non-Mycobacterium reference genomes (down to Bacteria) · mean identity 64.8%
detected down to outside the phylum (Proteobacteria/Firmicutes controls) — a universally conserved, ancient bacterial 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) 16 in the ORF — 0 in the essential state, 0 growth-defect, 16 non-essential, 0 growth-advantage. Saturation 0.812, mean read count 93.3076923077. 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.

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

Conditionlog2FCqEffect
fitness in mouse infection, day 45 (in vivo) -2.830.01 required
fitness in mouse infection (in vivo) +2.120.0052 disruption advantageous
fitness in mouse infection (in vivo) +1.630.042 disruption advantageous
fitness in mouse infection (in vivo) +1.600.025 disruption advantageous
fitness in mouse infection (in vivo) +1.430.042 disruption advantageous

Conditional fitness of transposon-disruption mutants across 5 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 16 of 16 independent MS datasets
Integrated abundance4556.0 ppm · rank 21/3519 (99.4th 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.

Physico-chemical properties (computed, ProtParam)

Length539 aa
Molecular weight55.9 kDa
Theoretical pI4.98
GRAVY0.11 (hydrophobic)
Aliphatic index105.8
Aromaticity0.032
Instability index23.6 (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)

PfamAccessioni-EvalueResiduesDescription
Cpn60_TCP1PF00118.30 2.7e-7122–525 TCP-1/cpn60 chaperonin family

Experimental structures (Protein Data Bank) 1 solved

PDBMethodResolutionCoverage
3m6c X-ray diffraction 2.2 Å 36%

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 92.8

PDB hitprobTM-scoreE-valueDescription
5opw-assembly1_A 1.00 0.85 8.4e-63 sig 5opw-assembly1_A Crystal structure of the GroEL mutant A109C
1kp8-assembly1_C 1.00 0.85 6.8e-62 sig 1kp8-assembly1_C Structural Basis for GroEL-assisted Protein Folding from the Crystal Structure of (GroEL-KMgATP)14 at 2.0 A Resolution
4wsc-assembly1_C 1.00 0.84 3.8e-62 sig 4wsc-assembly1_C Crystal structure of a GroELK105A mutant
9c0d-assembly1_I 1.00 0.85 3.6e-62 sig 9c0d-assembly1_I E.Faecium GroEL
2c7e-assembly1_A 1.00 0.86 8.8e-61 sig 2c7e-assembly1_A REVISED ATOMIC STRUCTURE FITTING INTO A GROEL(D398A)-ATP7 CRYO-EM MAP (EMD 1047)

Foldseek search of the AlphaFold DB model (mean pLDDT 92.8, 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)whiB3 (+ strand, 71 bp gap)
Downstream (3' on genome)groES (- strand, 94 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) transcription factor

Regulated by (1 TF) groEL1 (activates)
Regulonthis transcription factor regulates 1 target gene(s)

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: groES (chaperonin GroES), high confidence from genomic context alone (score 998 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3418c groES exp chaperonin GroES 999 998 ctx neighborhood:776 cooccurence:772 coexpression:831 experimental:829 textmining:953
Rv0440 groEL2 exp molecular chaperone GroEL 982 982 coexpression:825 database:900
Rv0087 hycE exp formate hydrogenase HycE 966 965 experimental:965
Rv0351 grpE exp stress response protein GrpE 981 929 coexpression:747 experimental:437 database:455 textmining:753
Rv0350 dnaK exp chaperone protein DnaK 988 868 coexpression:648 experimental:410 textmining:917
Rv0352 dnaJ1 exp chaperone protein DnaJ 973 862 coexpression:613 database:493 textmining:815
Rv2373c dnaJ2 exp chaperone protein DnaJ 940 846 coexpression:555 database:493 textmining:626
Rv2264c hyp exp hypothetical protein 853 829 coexpression:629 experimental:410
Rv0312 hyp exp hypothetical protein 851 828 coexpression:627 experimental:410
Rv2299c htpG exp chaperone protein HtpG 942 827 coexpression:715 experimental:416 textmining:681
Rv3446c hyp exp hypothetical protein 829 802 coexpression:627 experimental:410
Rv3433c nnr bifunctional ADP-dependent (S)-NAD(P)H-hydrate dehydratase/NAD(P)H-hydrate epimerase 734 735 coexpression:648
Rv1310 atpD exp ATP synthase subunit beta 806 694 database:551
Rv3610c ftsH exp zinc metalloprotease FtsH 760 636 database:404
Rv2460c clpP2 ATP-dependent CLP protease proteolytic subunit 2 739 631 coexpression:423

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: chaperonin GroEL
  • MTBC0 PGAP product: chaperonin GroEL
  • Pfam (hmmscan --cut_ga): Cpn60_TCP1 PF00118.30 (E=3e-71)
  • (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_217934.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Cpn60_TCP1 (PF00118.30)
  • 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 COG0459
  • Curated reference: UniProt P9WPE9 (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 92.8)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 164 functional partner(s); context anchor groES
  • 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)
  • 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_003631|Rv3417c|groEL1
MSKLIEYDETARRAMEVGMDKLADTVRVTLGPRGRHVVLAKAFGGPTVTNDGVTVAREIELEDPFEDLGAQLVKSVATKTNDVAGDGTTTATILAQALIKGGLRLVAAGVNPIALGVGIGKAADAVSEALLASATPVSGKTGIAQVATVSSRDEQIGDLVGEAMSKVGHDGVVSVEESSTLGTELEFTEGIGFDKGFLSAYFVTDFDNQQAVLEDALILLHQDKISSLPDLLPLLEKVAGTGKPLLIVAEDVEGEALATLVVNAIRKTLKAVAVKGPYFGDRRKAFLEDLAVVTGGQVVNPDAGMVLREVGLEVLGSARRVVVSKDDTVIVDGGGTAEAVANRAKHLRAEIDKSDSDWDREKLGERLAKLAGGVAVIKVGAATETALKERKESVEDAVAAAKAAVEEGIVPGGGASLIHQARKALTELRASLTGDEVLGVDVFSEALAAPLFWIAANAGLDGSVVVNKVSELPAGHGLNVNTLSYGDLAADGVIDPVKVTRSAVLNASSVARMVLTTETVVVDKPAKAEDHDHHHGHAH