mbtD Resolved · high auto-curated

H37Rv Rv2381c · MTBC0 mtbc0_002533 · 1004 aa · 2691448–2694462 (-) · RefSeq NP_216897.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)polyketide synthetase
MTBC0 PGAP re-annotationmycobactin polyketide synthase MbtD
Revised (this work)Mycobactin polyketide synthase MbtD. Pfam: Acyl_transf_1 (PF00698.27), KR (PF08659.17), adh_short (PF00106.32), Epimerase (PF01370.28), PP-binding (PF00550.32).

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

Curated reference (UniProt)

UniProt P71719 TrEMBL · unreviewed · Evidence at protein level
UniProt namePolyketide synthetase MbtD

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category I Lipid transport and metabolism
Q Secondary metabolites biosynthesis, transport and catabolism
Preferred namembtD
eggNOG descriptionpolyketide synthase
Orthologous groupCOG0236
KEGG orthology K04791
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 0.365 · purifying
Polymorphic sites (≥ 0.1% of strains) 8 synonymous, 7 missense, 1 nonsense, 0 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 0.34% of strains (493) · 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
Acyl_transf_1PF00698.27 1.7e-5099–409 Acyl transferase domain
KRPF08659.17 2.6e-34669–840 KR domain
adh_shortPF00106.32 9.9e-10669–826 short chain dehydrogenase
EpimerasePF01370.28 1.8e-06669–797 NAD dependent epimerase/dehydratase family
PP-bindingPF00550.32 2.4e-09920–976 Phosphopantetheine attachment site

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

Closest characterised functional partner: mbtC (polyketide synthetase), high confidence from genomic context alone (score 993 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2382c mbtC polyketide synthetase 998 993 ctx neighborhood:773 cooccurence:773 coexpression:860 textmining:806
Rv2383c mbtB phenyloxazoline synthase 998 991 ctx neighborhood:800 cooccurence:504 coexpression:897 textmining:859
Rv2380c mbtE peptide synthetase 995 978 ctx neighborhood:503 cooccurence:597 coexpression:870 textmining:817
Rv2379c mbtF peptide synthetase 994 970 ctx neighborhood:495 cooccurence:548 coexpression:845 textmining:814
Rv2378c mbtG L-lysine N6-monooxygenase 982 909 ctx neighborhood:502 coexpression:785 textmining:813
Rv0101 nrp peptide synthetase Nrp 844 814 ctx cooccurence:572 coexpression:438
Rv2947c pks15 polyketide synthase 796 796 ctx cooccurence:773
Rv2386c mbtI salicylate synthase 926 784 coexpression:780 textmining:673
Rv1180 pks3 polyketide beta-ketoacyl synthase 782 783 ctx cooccurence:773
Rv2928 tesA thioesterase TesA 706 694 ctx cooccurence:644
Rv2384 mbtA 2,3-dihydroxybenzoate-AMP ligase 929 636 ctx neighborhood:559 textmining:814
Rv2933 ppsC phthiocerol synthesis polyketide synthase type I PpsC 639 616 experimental:408
Rv3825c pks2 phthioceranic/hydroxyphthioceranic acid synthase 639 616 experimental:408
Rv1527c pks5 polyketide synthase 638 616 experimental:408
Rv2940c mas multifunctional mycocerosic acid synthase 640 614 experimental:408

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: mycobactin polyketide synthase MbtD
  • Pfam (hmmscan --cut_ga): Acyl_transf_1 PF00698.27 (E=2e-50), KR PF08659.17 (E=3e-34), adh_short PF00106.32 (E=1e-09), Epimerase PF01370.28 (E=2e-06), PP-binding PF00550.32 (E=2e-09)
  • (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_216897.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Acyl_transf_1 (PF00698.27), KR (PF08659.17), adh_short (PF00106.32), Epimerase (PF01370.28), PP-binding (PF00550.32)
  • 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 COG0236
  • Curated reference: UniProt P71719 (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 — 74 functional partner(s); context anchor mbtC
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002533|Rv2381c|mbtD
MAPKQLPDGRVAVLLSAHAEELIGPDARAIADYLERFPATTVTEVARQLRKTRRVRRHRAVLRAADRLELAEGLRALAAGREHPLIARSSLGSAPRQAFVFPGQGGHWPGMGAVAYRELPTYRTATDTCAAAFAAAGVDSPLPYLIAPPGTDERQAFCEIEIEGAQFVHAVALAEVWRSCGVLPDLTVGHSLGEVAAAYLAGSITLSDAVAVVAARANVVGRLPGRYAVAALGIGEQDASALIATTGGWLELSVVNASSTVAVSGERQAVAAIVDTVRSSGHFARGITVGFPVHTSVLESLRDELCEQLPDSEFMEAPVQFIGGTTGDVVAPGTTFGDYWYANLRHTVRFDRAVESAIRCGARAFIEISAHPALLFAIGQNCEGAANLPDGPAVLVGSARRGERFVDALSANIVSAAVADPGYPWGDLGGDPLDGDVDLSGFPNAPMRAVPMWAHPEPLPPVSGLTIAVERWERMVPSTPVAGRHRHLAVLDLGAHRALAQTLCAAIDSHPDTELSAARDAELILVIAPDFEHTDAVRAAGALADLVGAGLLDYPMHIGARCQSVCLVTVGAEQVDAADAVPSAGQAALAAMHRSIGFEHPEQTFSHLDLPSWDLDPVLGVSVITAVLRGFGETALRGSVNGYTLFERTLADAPAVPNWSLDSGVLDDVVVTGGAGAIGMHYARYLAEHGARRIVLLSRRAADQATVAMLRKQHGTVIVSPPCDITDPTQLSAIAAEYGGVGASLIVHAAGSVISGTAPGVTSAAVVDNFAAKVLGLAQMIELWPLRPDVRTLLCSSVMGVWGGHGVVAYSAANRLLDVMAAQLRAQGRHCVAVKWGLWQAPKAGEPARGIADAVTIARVERSGLRQMAPQQAIEASLHEFTVDPLVFAADAARLQMLLDSRQFERYEGPTDPNLTIVDAVRTQLAAVLGIPQAGEVNLQESLFDLGVDSMLALDLRNRLKRSIGATVSLATLMGDITGDGLVAKLEDADERSHTAQKVDISRD