fadD23 Resolved · high auto-curated

H37Rv Rv3826 · MTBC0 mtbc0_004055 · 584 aa · 4323922–4325676 (+) · RefSeq NP_218343.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)long-chain-fatty-acid--CoA ligase FadD23
MTBC0 PGAP re-annotationlong-chain-fatty-acid--CoA ligase FadD23
Revised (this work)Long-chain-fatty-acid--CoA ligase FadD23. Pfam: AMP-binding (PF00501.35), AMP-dom_DIP2-like (PF23024.2).

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

Curated reference (UniProt)

UniProt P9WQ47 SwissProt · reviewed · Evidence at protein level
UniProt nameLong-chain-fatty-acid--AMP ligase FadD23
EC (curated) EC 6.2.1.57
Curated functionCatalyzes the activation of long-chain fatty acids as acyl-adenylates (acyl-AMP), which are then transferred to the multifunctional polyketide synthase (PKS) type III for further chain extension (Probable). Involved in the biosynthesis of sulfolipid 1 (SL-1).

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category I Lipid transport and metabolism
Q Secondary metabolites biosynthesis, transport and catabolism
Preferred namefadD28
eggNOG descriptionActivates fatty acids by binding to coenzyme A
Orthologous groupCOG0318
EC number EC 2.7.7.95, EC 6.2.1.51
KEGG orthology K00666, K12423, K12425, K12426, K12427, K12428, K21059
Gene Ontology (45) GO:0003674, GO:0003824, GO:0005575, GO:0005623, GO:0005886, GO:0006082, GO:0006629, GO:0006631, GO:0006633, GO:0006790, GO:0008150, GO:0008152 +33 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 1.248 · diversifying/relaxed
Polymorphic sites (≥ 0.1% of strains) 3 synonymous, 11 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
AMP-bindingPF00501.35 2.1e-5712–415 AMP-binding enzyme
AMP-dom_DIP2-likePF23024.2 5.0e-09463–571 Disco-interacting protein 2-like, AMP domain

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

Closest characterised functional partner: mbtE (peptide synthetase), high confidence from genomic context alone (score 948 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2380c mbtE peptide synthetase 950 948 ctx fusion:631 cooccurence:690 experimental:465
Rv3825c pks2 phthioceranic/hydroxyphthioceranic acid synthase 942 866 ctx neighborhood:543 textmining:590
Rv2379c mbtF peptide synthetase 837 836 ctx cooccurence:657
Rv0101 nrp peptide synthetase Nrp 810 800 ctx cooccurence:670
Rv2947c pks15 polyketide synthase 786 786 ctx fusion:532
Rv2932 ppsB phthiocerol synthesis polyketide synthase type I PpsB 760 746
Rv1180 pks3 polyketide beta-ketoacyl synthase 778 744 ctx fusion:418
Rv1527c pks5 polyketide synthase 767 744
Rv0405 pks6 membrane bound polyketide synthase 754 742
Rv2933 ppsC phthiocerol synthesis polyketide synthase type I PpsC 762 741
Rv2940c mas multifunctional mycocerosic acid synthase 798 739
Rv2383c mbtB phenyloxazoline synthase 764 739 ctx fusion:451
Rv2382c mbtC polyketide synthetase 740 731 ctx fusion:438
Rv2931 ppsA phthiocerol synthesis polyketide synthase type I PpsA 798 718
Rv3800c pks13 polyketide synthase 739 714

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: long-chain-fatty-acid--CoA ligase FadD23
  • MTBC0 PGAP product: long-chain-fatty-acid--CoA ligase FadD23
  • Pfam (hmmscan --cut_ga): AMP-binding PF00501.35 (E=2e-57), AMP-dom_DIP2-like PF23024.2 (E=5e-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_218343.1)
  • Domains: Pfam-A via hmmscan --cut_ga — AMP-binding (PF00501.35), AMP-dom_DIP2-like (PF23024.2)
  • 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 COG0318
  • Curated reference: UniProt P9WQ47 (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)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 87 functional partner(s); context anchor mbtE
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_004055|Rv3826|fadD23
MVSLSIPSMLRQCVNLHPDGTAFTYIDYERDSEGISESLTWSQVYRRTLNVAAEVRRHAAIGDRAVILAPQGLDYIVAFLGALQAGLIAVPLSAPLGGASDERVDAVVRDAKPNVVLTTSAIMGDVVPRVTPPPGIASPPTVAVDQLDLDSPIRSNIVDDSLQTTAYLQYTSGSTRTPAGVMITYKNILANFQQMISAYFADTGAVPPLDLFIMSWLPFYHDMGLVLGVCAPIIVGCGAVLTSPVAFLQRPARWLQLMAREGQAFSAAPNFAFELTAAKAIDDDLAGLDLGRIKTILCGSERVHPATLKRFVDRFSRFNLREFAIRPAYGLAEATVYVATSQAGQPPEIRYFEPHELSAGQAKPCATGAGTALVSYPLPQSPIVRIVDPNTNTECPPGTIGEIWVHGDNVAGGYWEKPDETERTFGGALVAPSAGTPVGPWLRTGDSGFVSEDKFFIIGRIKDLLIVYGRNHSPDDIEATIQEITRGRCAAIAVPSNGVEKLVAIVELNNRGNLDTERLSFVTREVTSAISTSHGLSVSDLVLVAPGSIPITTSGKVRRAECVKLYRHNEFTRLDAKPLQASDL