pks8 Resolved · high auto-curated

H37Rv Rv1662 · MTBC0 - · 1602 aa · 1881704–1886512 (+) · RefSeq NP_216178.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)polyketide synthase
MTBC0 PGAP re-annotation
Revised (this work)Polyketide synthase. Pfam: Docking (PF08990.17), ketoacyl-synt (PF00109.33), Thiolase_N (PF00108.30), Ketoacyl-synt_C (PF02801.29), KAsynt_C_assoc (PF16197.12), CurL-like_PKS_C (PF22621.3), RhiE-like_linker (PF22336.3), Acyl_transf_1 (PF00698.27), PKS_DH_N (PF21089.4), PS-DH (PF14765.13), SpnB_Rossmann (PF22953.4), ADH_N (PF08240.18), ADH_zinc_N (PF00107.33), ADH_zinc_N_2 (PF13602.13).

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).

Curated reference (UniProt)

UniProt O65933 TrEMBL · unreviewed · Predicted
UniProt nameProbable polyketide synthase Pks8

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category Q Secondary metabolites biosynthesis, transport and catabolism
Preferred namepks8
eggNOG descriptionpolyketide synthase
Orthologous groupCOG0604
KEGG orthology K12435

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) pseudogene candidate

pN/pS 0.572 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 18 synonymous, 28 missense, 0 nonsense, 2 frameshift
Disruption 2 distinct premature-stop/frameshift site(s); most common in 5.13% of strains (7444) · 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.

Domains (Pfam, hmmscan --cut_ga)

PfamAccessioni-EvalueResiduesDescription
DockingPF08990.17 1.3e-077–30 Erythronolide synthase docking domain
ketoacyl-syntPF00109.33 4.5e-9634–281 Beta-ketoacyl synthase, N-terminal domain
Thiolase_NPF00108.30 1.0e-06188–235 Thiolase, N-terminal domain
Ketoacyl-synt_CPF02801.29 2.2e-42289–404 Beta-ketoacyl synthase, C-terminal domain
KAsynt_C_assocPF16197.12 2.4e-12407–526 Ketoacyl-synthetase C-terminal extension
CurL-like_PKS_CPF22621.3 2.5e-09477–534 CurL-like, PKS C-terminal
RhiE-like_linkerPF22336.3 2.2e-07477–544 RhiE-like, KS-MAT linker domain
Acyl_transf_1PF00698.27 7.3e-63561–872 Acyl transferase domain
PKS_DH_NPF21089.4 5.2e-25921–1020 Polyketide synthase dehydratase domain
PS-DHPF14765.13 2.5e-251044–1189 Polyketide synthase dehydratase N-terminal domain
SpnB_RossmannPF22953.4 7.5e-311217–1330 Polyketide synthase extender module SpnB, Rossmann fold domain
ADH_NPF08240.18 1.0e-091373–1449 Alcohol dehydrogenase GroES-like domain
ADH_zinc_NPF00107.33 1.7e-101491–1582 Zinc-binding dehydrogenase
ADH_zinc_N_2PF13602.13 1.1e-061527–1582 Zinc-binding dehydrogenase

Functional interaction network (STRING v12, guilt-by-association)

Closest characterised functional partner: pks17 (polyketide synthase), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1663 pks17 polyketide synthase 999 1000 ctx neighborhood:792 fusion:899 cooccurence:774 coexpression:816 database:900 textmining:883
Rv1661 pks7 polyketide synthase 981 979 ctx neighborhood:748 coexpression:863 experimental:433
Rv1664 pks9 polyketide synthase 967 965 ctx neighborhood:781 coexpression:806
Rv2383c mbtB phenyloxazoline synthase 940 891 ctx neighborhood:544 cooccurence:456 coexpression:409 textmining:478
Rv1527c pks5 polyketide synthase 907 868 experimental:791
Rv3825c pks2 phthioceranic/hydroxyphthioceranic acid synthase 905 868 experimental:791
Rv2933 ppsC phthiocerol synthesis polyketide synthase type I PpsC 901 868 experimental:791
Rv2940c mas multifunctional mycocerosic acid synthase 904 867 experimental:791
Rv2048c pks12 polyketide synthase 883 841 experimental:791
Rv0101 nrp peptide synthetase Nrp 869 828 ctx cooccurence:565 coexpression:421
Rv2928 tesA thioesterase TesA 781 761 ctx cooccurence:714
Rv2380c mbtE peptide synthetase 805 748 ctx cooccurence:527
Rv3800c pks13 polyketide synthase 793 707 coexpression:425
Rv2379c mbtF peptide synthetase 680 661 ctx cooccurence:474
Rv1181 pks4 polyketide beta-ketoacyl synthase 701 652 experimental:433

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 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): polyketide synthase
  • Pfam (hmmscan --cut_ga): Docking PF08990.17 (E=1e-07), ketoacyl-synt PF00109.33 (E=5e-96), Thiolase_N PF00108.30 (E=1e-06), Ketoacyl-synt_C PF02801.29 (E=2e-42), KAsynt_C_assoc PF16197.12 (E=2e-12), CurL-like_PKS_C PF22621.3 (E=3e-09), RhiE-like_linker PF22336.3 (E=2e-07), Acyl_transf_1 PF00698.27 (E=7e-63), PKS_DH_N PF21089.4 (E=5e-25), PS-DH PF14765.13 (E=2e-25), SpnB_Rossmann PF22953.4 (E=7e-31), ADH_N PF08240.18 (E=1e-09), ADH_zinc_N PF00107.33 (E=2e-10), ADH_zinc_N_2 PF13602.13 (E=1e-06)
  • (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_216178.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Docking (PF08990.17), ketoacyl-synt (PF00109.33), Thiolase_N (PF00108.30), Ketoacyl-synt_C (PF02801.29), KAsynt_C_assoc (PF16197.12), CurL-like_PKS_C (PF22621.3), RhiE-like_linker (PF22336.3), Acyl_transf_1 (PF00698.27), PKS_DH_N (PF21089.4), PS-DH (PF14765.13), SpnB_Rossmann (PF22953.4), ADH_N (PF08240.18), ADH_zinc_N (PF00107.33), ADH_zinc_N_2 (PF13602.13)
  • 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 COG0604
  • Curated reference: UniProt O65933 (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)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 78 functional partner(s); context anchor pks17
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv1662|pks8
MSGTTTHVDYLKRLTADLRRTRRRLSDLEAKLSEPVAVVGMGCRYPGGVDSPETLWELVAQGRDAVSDFPADRGWDVDGLFDPDPDACGKMYTRRGTFLEHAGDFDAGFFGIGPSEALAMDPQQRLLLEVSWEALERTGIDPTKLRGSATGVFAGVIHAGYGGQLSGELEGYGLTGSTLSVASGRVAYVLGLEGPAVSVDTACSSSLVALHLAVQSLRSGECDLALAGGVTVMATPAAFVEFSRQRALARDGRCKVYAGAADGTAWSEGAGVLVVERLVDARRLGHPVLALVRGSAVNQDGASNGLTAPNGPSQQRVIRAALASARLRAVEVDVVEGHGTGTMLGDPIEAQALLATYGQDRVEPLWLGSIKSNIGHTSAAAGVAGVIKMVQAMRHGVMPKTLHVDVPTPHVDWSVGAVSLLTQPRAWSVHGRPRRAGVSSFGISGTNAHVILEQAPVVESVVPEVASPTAASAVPWVLSARSEQALAGQAQRLLAFVAANPDLDPIDVGWSLVKTRAMFEHRAVVVGADRGALLAGLAALAAGESGAGVAVGRARSVGKTVFVFPGQGAQWVGMGAQLYAELPLFALAFDAVAEELDRHLRLPLRNVLWEGDEALLTSTEFAQPALFAIEVALATLLQHWGISPDFLIGHSVGEIAAAHLAGVLSLTDAAGLVAARGRLMAELPAGGVMVVVAASEEEVLPVLVDGANLAAVNAPHSVVVSGCEAAVSDIADHFARRGRRVHRLAVSHAFHSLLMEPMLAEFTRIAAGISVSKPRIPLVSNVTGQMAGAGYGDGQYWVEHARRPVRFAEGVQLLNAVGATRFVEVGPGGGLTALVEQSLPLGEALSVAMMRREHPEVSSVLGAVATLFTAGAQMDWPAVFGSPGRRIELPTYAFQRQRYWLPPTSAGSADISGVGLLAARHGLLGAVVEQPDSDVVVLTGRLSVGEQRWLADHVIAGVVLLAGAAFVELALRAADQVDCGVVEELTVVTPLVLPTVGGVQLQVVVGVGEMGQRPVSIYSRNAESDSGWVLHARGVLGAKAVAPAADLSVWPPLGAAPVDVDGAYQRFAELGYEYGRAFQGLTAMWRRESELFADVAVPDDVDVTLSGFGIHPLVLDAALHAMGMVGEQAATMLPFSWQGVSLHAAGASRVRARIAPAGDGTVSVELADQAGLPVLSVQALVMRSVSSQLLSAAVAAADAAGRGLLEVAWLPVELAHNDISADLVVWELESFQDGVGPVYSATHRVLVALQSWLAQERAGRLVVLTQGSVGQDATNLAGAAVWGLVRSAQAEHPGRVMLVDSDGSMDVGDVIGCGEEQLMIRNGTAYAARLAQLRPQPILQLPDTNSGWRLVAGGAGALEDLTLASCPAKELAPGQVRIEVRALGVNFRDVLVALGIYPGAAELGAEGAGVVTEVGPGVTGLAVGDPVMGLLGVAGSEAVVDARLVVKLPNRWPLTDAAGVPVVFLTAYYALRVLAQVQPGESVLVHAAAGGVGMAAVQLARLWGLEVFATASRGKWDTLHTMGCDNTHVADSRTLAFEETFWLTTEGRGVDVVLNSLAGEFTDASLRLLPRGGRFIEMGKTEFGTPRSLPRTILGWPTGLST