pks11 Resolved · high auto-curated

H37Rv Rv1665 · MTBC0 mtbc0_001773 · 353 aa · 1903269–1904330 MTBC0 (+) · RefSeq NP_216181.1

Genomic neighbourhood (genome browser)

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Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)chalcone synthase
MTBC0 PGAP re-annotationtype III polyketide synthase
Revised (this work)Type III polyketide synthase. Pfam: Chal_sti_synt_N (PF00195.26), FAE1_CUT1_RppA (PF08392.19), Chal_sti_synt_C (PF02797.22), ACP_syn_III_C (PF08541.17).
Functional category (TubercuList)lipid metabolism

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) 4 publications

4 TB publications mention this gene. 4 publication(s) discuss this gene (3 in a M. tuberculosis context, 1 in other mycobacteria — M. marinum (1)).

PublicationDate
Novel Type III Polyketide Synthases Biosynthesize Methylated Polyketides in Mycobacterium marinum. doi:10.1038/s41598-018-24980-1 2018
Crystal structure of Mycobacterium tuberculosis polyketide synthase 11 (PKS11) reveals intermediates in the synthesis of methyl-branched alkylpyrones. doi:10.1074/jbc.M113.468892 2013
Inactivation of polyketide synthase and related genes results in the loss of complex lipids in Mycobacterium tuberculosis H37Rv. doi:10.1111/j.1472-765X.2005.01659.x 2005
A new family of type III polyketide synthases in Mycobacterium tuberculosis. doi:10.1074/jbc.M306714200 2003

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.

Genomic-neighbour overlap (structural caveat) antiparallel · 2 % of gene

Neighbourcyp139A3 (Rv1666c, - strand)
Overlap18 bp, 2 % of this gene's length

antiparallel overlap: this gene may inherit essentiality/conservation signal from its neighbour through shared TA sites or promoter constraint, without any protein of its own being produced (cf. Rv2438A/nadE) Signals attributed to this gene (Tn-seq essentiality via shared TA sites, conservation via promoter constraint) should be cross-checked against the neighbour before being read as its own. P20.1, derived from GFF3 gene coordinates, 2026-08-03.

Conditional expression context (iModulons)

Member of 1 independently-modulated gene set(s): Central Carbon Metabolism.

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 0.81 (95% CI -3.35 to 6.07). 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 functionPossibly involved in the biosynthesis of secondary metabolites [catalytic activity: 3 malonyl-CoA + 4-coumaroyl-CoA = 4 CoA + naringenin chalcone + 3 CO2]
Mycobrowser EC 2.3.1.74 · superseded EC numbering; the atlas uses the current class (2.3.1.-)

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 Mb1693 · 100.0% identity
M. marinum MMAR_2474 · 84.1% identity
M. orygis RJtmp_001741 · 100.0% 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 P9WPF3 SwissProt · reviewed · Evidence at protein level
UniProt nameMethyl-branched alkylpyrone synthesis polyketide synthase-like Pks11
EC (curated) EC 2.3.1.-
Curated functionInvolved in the biosynthesis of methyl-branched alkylpyrones. Pks11 catalyzes the extension of medium- and long-chain aliphatic acyl-CoA substrates by using malonyl-CoA and methylmalonyl-CoA as extender molecules to synthesize polyketide products. Palmitoyl-CoA or a similar long chain fatty acid derivative is the likely substrate in vivo.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category Q Secondary metabolites biosynthesis, transport and catabolism
Preferred namepks11
eggNOG descriptionsynthase
Orthologous groupCOG3424
KEGG orthology K16167
Gene Ontology (43) GO:0005575, GO:0005622, GO:0005623, GO:0005737, GO:0006629, GO:0006725, GO:0008150, GO:0008152, GO:0008610, GO:0009058, GO:0009273, GO:0009698 +31 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 0.607 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 3 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

Genus-wide presence (~53 non-MTBC Mycobacterium) present in 50/53 (94%) · mean identity 76.5% · 4/4 closest MTBAP relatives
conserved across the genus (present in 50/53 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 Bacteria) · mean identity 39.9%
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) 13 in the ORF — 0 in the essential state, 0 growth-defect, 13 non-essential, 0 growth-advantage. Saturation 1.000, mean read count 102.923076923. 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 (in vivo) +1.370.023 disruption advantageous

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 detectiondetected in 15 of 16 independent MS datasets
Integrated abundance109.0 ppm · rank 1236/3519 (64.9th 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)

Length353 aa
Molecular weight37.6 kDa
Theoretical pI5.49
GRAVY0.163 (hydrophobic)
Aliphatic index108.6
Aromaticity0.054
Instability index50.7 (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
Chal_sti_synt_NPF00195.26 2.2e-219–197 Chalcone and stilbene synthases, N-terminal domain
FAE1_CUT1_RppAPF08392.19 2.4e-1487–199 FAE1/Type III polyketide synthase-like protein
Chal_sti_synt_CPF02797.22 1.9e-16219–351 Chalcone and stilbene synthases, C-terminal domain
ACP_syn_III_CPF08541.17 4.6e-10261–352 3-Oxoacyl-[acyl-carrier-protein (ACP)] synthase III C terminal

Experimental structures (Protein Data Bank) 6 solved

PDBMethodResolutionCoverage
4jaq X-ray diffraction 1.73 Å 100%
4jap X-ray diffraction 1.833 Å 100%
4jar X-ray diffraction 1.98 Å 100%
4jao X-ray diffraction 2.05 Å 100%
4jd3 X-ray diffraction 2.25 Å 100%
4jat X-ray diffraction 2.42 Å 100%

Experimentally solved structures mapped from the UniProt accession via PDBe/SIFTS (6 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 97.4

PDB hitprobTM-scoreE-valueDescription
4jap-assembly1_D 1.00 1.00 4.9e-72 sig 4jap-assembly1_D Crystal Structure of Mycobacterium tuberculosis PKS11 Reveals Intermediates in the Synthesis of Methyl-branched Alkylpyrones
4jd3-assembly2_D 1.00 1.00 1.8e-67 sig 4jd3-assembly2_D Crystal Structure of Mycobacterium tuberculosis PKS11 Reveals Intermediates in the Synthesis of Methyl-branched Alkylpyrones
6j1n-assembly1_B 1.00 0.90 3.8e-33 sig 6j1n-assembly1_B Anisodus acutangulus type III polyketide sythase AaPKS2 in complex with 4-carboxy-3-oxobutanoyl-CoA
1ee0-assembly1_B 1.00 0.91 1.3e-32 sig 1ee0-assembly1_B 2-PYRONE SYNTHASE COMPLEXED WITH ACETOACETYL-COA
4wum-assembly1_B 1.00 0.91 9.9e-33 sig 4wum-assembly1_B X-ray crystal structure of Chalcone Synthase from Freesia hybrida

Foldseek search of the AlphaFold DB model (mean pLDDT 97.4, 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)pks9 (+ strand, 146 bp gap)
Downstream (3' on genome)cyp139 (- strand, -18 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)

Regulated by (1 TF) lsr2 (activates)

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: Rv1138c (oxidoreductase), high confidence from genomic context alone (score 786 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1139c hyp hypothetical protein 904 871 ctx cooccurence:774
Rv2932 ppsB exp phthiocerol synthesis polyketide synthase type I PpsB 873 855 experimental:470 database:720
Rv2933 ppsC exp phthiocerol synthesis polyketide synthase type I PpsC 910 832 database:720 textmining:490
Rv1660 pks10 exp chalcone synthase 812 810 database:720
Rv1181 pks4 exp polyketide beta-ketoacyl synthase 829 805 database:720
Rv2931 ppsA exp phthiocerol synthesis polyketide synthase type I PpsA 816 804 database:720
Rv1138c oxidoreductase 847 786 ctx cooccurence:762
Rv0667 rpoB exp DNA-directed RNA polymerase subunit beta 801 772 experimental:406 database:628
Rv1390 rpoZ exp DNA-directed RNA polymerase subunit omega 770 771 experimental:406 database:629
Rv3457c rpoA exp DNA-directed RNA polymerase subunit alpha 757 758 database:626
Rv1305 atpE exp ATP synthase subunit C 764 754 database:610
Rv1180 pks3 exp polyketide beta-ketoacyl synthase 747 738 database:720
Rv2934 ppsD exp phthiocerol synthesis polyketide synthase type I PpsD 819 729 database:720
Rv2935 ppsE exp phthiocerol synthesis polyketide synthase type I PpsE 742 729 database:720
Rv1663 pks17 polyketide synthase 959 685 ctx neighborhood:494 textmining:878

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: chalcone synthase
  • MTBC0 PGAP product: type III polyketide synthase
  • Pfam (hmmscan --cut_ga): Chal_sti_synt_N PF00195.26 (E=2e-21), FAE1_CUT1_RppA PF08392.19 (E=2e-14), Chal_sti_synt_C PF02797.22 (E=2e-16), ACP_syn_III_C PF08541.17 (E=5e-10)
  • (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_216181.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Chal_sti_synt_N (PF00195.26), FAE1_CUT1_RppA (PF08392.19), Chal_sti_synt_C (PF02797.22), ACP_syn_III_C (PF08541.17)
  • 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 COG3424
  • Curated reference: UniProt P9WPF3 (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 97.4)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 41 functional partner(s); context anchor Rv1138c
  • 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_001773|Rv1665|pks11
MSVIAGVFGALPPHRYSQSEITDSFVEFPGLKEHEEIIRRLHAAAKVNGRHLVLPLQQYPSLTDFGDANEIFIEKAVDLGVEALLGALDDANLRPSDIDMIATATVTGVAVPSLDARIAGRLGLRPDVRRMPLFGLGCVAGAAGVARLRDYLRGAPDDVAVLVSVELCSLTYPAVKPTVSSLVGTALFGDGAAAVVAVGDRRAEQVRAGGPDILDSRSSLYPDSLHIMGWDVGSHGLRLRLSPDLTNLIERYLANDVTTFLDAHRLTKDDIGAWVSHPGGPKVIDAVATSLALPPEALELTWRSLGEIGNLSSASILHILRDTIEKRPPSGSAGLMLAMGPGFCTELVLLRWR