papA5 Resolved · high auto-curated

H37Rv Rv2939 · MTBC0 mtbc0_003122 · 422 aa · 3295946–3297214 (+) · RefSeq NP_217455.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)phthiocerol/phthiodiolone dimycocerosyl transferase
MTBC0 PGAP re-annotationphthiocerol/phthiodiolone dimycocerosyl transferase
Revised (this work)Phthiocerol/phthiodiolone dimycocerosyl transferase. Pfam: PapA_C (PF16911.11).

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

Curated reference (UniProt)

UniProt P9WIN5 SwissProt · reviewed · Evidence at protein level
UniProt namePhthiocerol/phthiodiolone dimycocerosyl transferase
EC (curated) EC 2.3.1.282
Curated functionCatalyzes diesterification of phthiocerol, phthiodiolone, and phenolphthiocerol with mycocerosic acids, the final step in the phthiocerol, phthiodiolone and phenolphthiocerol dimycocerosate esters (PDIM) synthesis. Can directly transfer the mycocerosate bound to the mycocerosic acid synthase (mas) onto the substrate alcohols. Is also able to catalyze acyl transfer using various nucleophiles as acceptors and several acyl-CoA thioesters as donors in vitro; preference is observed for saturated medium chain alcohols and long chain acyl-CoA thioesters.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category Q Secondary metabolites biosynthesis, transport and catabolism
Preferred namepapA5
eggNOG descriptionCatalyzes diesterification of phthiocerol and phthiodiolone with mycocerosic acids, the final step in the phthiocerol and phthiodiolone dimycocerosate esters (PDIM) synthesis. Can directly transfer the mycocerosate bound to the mycocerosic acid synthase (mas) onto the substrate alcohols
Orthologous groupCOG1020
KEGG orthology K16023
KEGG pathways map01051, map01052, map01130
Gene Ontology (24) GO:0003674, GO:0003824, GO:0006629, GO:0008150, GO:0008152, GO:0008374, GO:0008610, GO:0009058, GO:0009273, GO:0009987, GO:0016043, GO:0016740 +12 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 0.344 · purifying
Polymorphic sites (≥ 0.1% of strains) 6 synonymous, 6 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
PapA_CPF16911.11 1.9e-63208–393 Phthiocerol/phthiodiolone dimycocerosyl transferase C-terminus

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

Closest characterised functional partner: drrB (daunorubicin ABC transporter permease DrrB), high confidence from genomic context alone (score 968 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2937 drrB daunorubicin ABC transporter permease DrrB 982 968 ctx neighborhood:674 coexpression:855 textmining:465
Rv2938 drrC daunorubicin ABC transporter permease DrrC 973 958 ctx neighborhood:689 coexpression:839
Rv2935 ppsE phthiocerol synthesis polyketide synthase type I PpsE 991 954 ctx neighborhood:622 cooccurence:436 coexpression:803 textmining:821
Rv2936 drrA daunorubicin ABC transporter ATP-binding protein DrrA 983 947 ctx neighborhood:668 coexpression:848 textmining:697
Rv2934 ppsD phthiocerol synthesis polyketide synthase type I PpsD 949 924 ctx neighborhood:614 coexpression:733
Rv2933 ppsC phthiocerol synthesis polyketide synthase type I PpsC 907 826 ctx neighborhood:656 coexpression:514 textmining:487
Rv2931 ppsA phthiocerol synthesis polyketide synthase type I PpsA 920 767 ctx neighborhood:632 textmining:672
Rv2932 ppsB phthiocerol synthesis polyketide synthase type I PpsB 800 744 ctx neighborhood:632
Rv2164c hyp hypothetical protein 742 743 ctx cooccurence:742
Rv3843c transmembrane protein 741 741 ctx cooccurence:741
Rv3903c cpnT hyp hypothetical protein 734 735 ctx cooccurence:732
Rv2945c lppX lipoprotein LppX 785 731 ctx cooccurence:587
Rv2948c fadD22 p-hydroxybenzoyl--AMP ligase 760 730 coexpression:730
Rv2423 hyp hypothetical protein 718 718 ctx cooccurence:718
Rv0538 membrane protein 715 715 ctx cooccurence: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: phthiocerol/phthiodiolone dimycocerosyl transferase
  • MTBC0 PGAP product: phthiocerol/phthiodiolone dimycocerosyl transferase
  • Pfam (hmmscan --cut_ga): PapA_C PF16911.11 (E=2e-63)
  • (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_217455.1)
  • Domains: Pfam-A via hmmscan --cut_ga — PapA_C (PF16911.11)
  • 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 COG1020
  • Curated reference: UniProt P9WIN5 (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 — 77 functional partner(s); context anchor drrB
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003122|Rv2939|papA5
MFPGSVIRKLSHSEEVFAQYEVFTSMTIQLRGVIDVDALSDAFDALLETHPVLASHLEQSSDGGWNLVADDLLHSGICVIDGTAATNGSPSGNAELRLDQSVSLLHLQLILREGGAELTLYLHHCMADGHHGAVLVDELFSRYTDAVTTGDPGPITPQPTPLSMEAVLAQRGIRKQGLSGAERFMSVMYAYEIPATETPAVLAHPGLPQAVPVTRLWLSKQQTSDLMAFGREHRLSLNAVVAAAILLTEWQLRNTPHVPIPYVYPVDLRFVLAPPVAPTEATNLLGAASYLAEIGPNTDIVDLASDIVATLRADLANGVIQQSGLHFGTAFEGTPPGLPPLVFCTDATSFPTMRTPPGLEIEDIKGQFYCSISVPLDLYSCAVYAGQLIIEHHGHIAEPGKSLEAIRSLLCTVPSEYGWIME