mbtC Resolved · high auto-curated

H37Rv Rv2382c · MTBC0 mtbc0_002534 · 444 aa · 2694462–2695796 (-) · RefSeq NP_216898.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)polyketide synthetase
MTBC0 PGAP re-annotationpolyketide synthetase MbtC
Revised (this work)Polyketide synthetase MbtC. Pfam: ketoacyl-synt (PF00109.33), Thiolase_N (PF00108.30), Ketoacyl-synt_C (PF02801.29).

Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.

Curated reference (UniProt)

UniProt P71718 TrEMBL · unreviewed · Evidence at protein level
UniProt namePolyketide synthetase MbtC

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category Q Secondary metabolites biosynthesis, transport and catabolism
Preferred namembtC
eggNOG descriptionBelongs to the beta-ketoacyl-ACP synthases family
Orthologous groupCOG3321
KEGG orthology K04790
KEGG pathways map01053

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 0.215 · purifying
Polymorphic sites (≥ 0.1% of strains) 5 synonymous, 3 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.

Domains (Pfam, hmmscan --cut_ga)

PfamAccessioni-EvalueResiduesDescription
ketoacyl-syntPF00109.33 2.2e-815–254 Beta-ketoacyl synthase, N-terminal domain
Thiolase_NPF00108.30 9.2e-08166–210 Thiolase, N-terminal domain
Ketoacyl-synt_CPF02801.29 1.3e-35262–378 Beta-ketoacyl synthase, C-terminal domain

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

Closest characterised functional partner: mbtB (phenyloxazoline synthase), high confidence from genomic context alone (score 998 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2383c mbtB phenyloxazoline synthase 999 998 ctx neighborhood:882 fusion:697 coexpression:913 textmining:942
Rv2380c mbtE peptide synthetase 999 995 ctx neighborhood:696 fusion:753 cooccurence:506 coexpression:848 textmining:882
Rv2381c mbtD polyketide synthetase 998 993 ctx neighborhood:773 cooccurence:773 coexpression:860 textmining:806
Rv2379c mbtF peptide synthetase 997 986 ctx neighborhood:721 fusion:465 cooccurence:454 coexpression:810 textmining:816
Rv1663 pks17 polyketide synthase 981 980 ctx fusion:900 cooccurence:773
Rv2946c pks1 polyketide synthase 979 979 ctx fusion:881 cooccurence:766
Rv1181 pks4 polyketide beta-ketoacyl synthase 937 930 ctx fusion:681 cooccurence:742
Rv3777 oxidoreductase 916 916 ctx fusion:900
Rv3141 fadB4 NADPH quinone oxidoreductase FadB 915 915 ctx fusion:899
Rv1912c fadB5 oxidoreductase FadB 914 913 ctx fusion:897
Rv2384 mbtA 2,3-dihydroxybenzoate-AMP ligase 982 854 ctx neighborhood:771 textmining:883
Rv2378c mbtG L-lysine N6-monooxygenase 989 851 ctx neighborhood:755 coexpression:415 textmining:932
Rv0101 nrp peptide synthetase Nrp 851 842 ctx cooccurence:482 coexpression:428
Rv2386c mbtI salicylate synthase 978 825 coexpression:819 textmining:880
Rv1529 fadD24 fatty-acid--CoA ligase FadD24 799 792 ctx fusion:557

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

  • Legacy H37Rv annotation: polyketide synthetase
  • MTBC0 PGAP product: polyketide synthetase MbtC
  • Pfam (hmmscan --cut_ga): ketoacyl-synt PF00109.33 (E=2e-81), Thiolase_N PF00108.30 (E=9e-08), Ketoacyl-synt_C PF02801.29 (E=1e-35)
  • (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_216898.1)
  • Domains: Pfam-A via hmmscan --cut_ga — ketoacyl-synt (PF00109.33), Thiolase_N (PF00108.30), Ketoacyl-synt_C (PF02801.29)
  • 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 COG3321
  • Curated reference: UniProt P71718 (TrEMBL, unreviewed; 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)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 73 functional partner(s); context anchor mbtB
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002534|Rv2382c|mbtC
MSDNDPVVIVGLAIEAPGGVETADDYWTLLSEQREGLGPFPTDRGWALRELFDGSRRNGFKPIHNLGGFLSSATTFDPEFFRISPREATAMDPQQRVGLRVAWRTLENSGINPDDLAGHDVGCYVGASALEYGPALTEFSHHSGHLITGTSLGVISGRIAYTLDLAGPALTVDTSCSSALAAFHTAVQAIRAGDCDLALAGGVCVMGTPGYFVEFSKQHALSDDGHCRPYSAHASGTAWAEGAAMFLLQRRSRATADRRRVLAEVRASCLNSDGLSDGLTAPSGDAQTRLLRRAIAQAAVVPADVGMVEGHGTATRLGDRTELRSLAASYGTAPAGRGPLLGSVKSNIGHAQAAAGGLGLVKVILAAQHAAIPPTLHVDEPSREIDWEKQGLRLADKLTPWRAVDGWRTAAVSAFGMSGTNSHVIVSMPDTVSAPERGPECGEV