entC Resolved · high auto-curated

H37Rv Rv3215 · MTBC0 mtbc0_003421 · 372 aa · 3614396–3615514 (+) · RefSeq NP_217731.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)isochorismate synthase
MTBC0 PGAP re-annotationisochorismate synthase
Revised (this work)Isochorismate synthase. Pfam: Chorismate_bind (PF00425.25).

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

Curated reference (UniProt)

UniProt P9WFW9 SwissProt · reviewed · Evidence at protein level
UniProt namePutative isochorismate synthase MenF
EC (curated) EC 5.4.4.2
Curated functionCatalyzes the conversion of chorismate to isochorismate.

UniProt still lists this protein as Putative isochorismate synthase MenF; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category H Coenzyme transport and metabolism
Q Secondary metabolites biosynthesis, transport and catabolism
Preferred nameentC
eggNOG descriptionIsochorismate synthase
Orthologous groupCOG1169
EC number EC 5.4.4.2
KEGG orthology K02361, K02552
KEGG pathways map00130, map01053, map01100, map01110, map01130
KEGG modules M00116

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 0.055 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 7 synonymous, 1 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
Chorismate_bindPF00425.25 8.2e-7197–360 chorismate binding enzyme

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

Closest characterised functional partner: mbtB (phenyloxazoline synthase), high confidence from genomic context alone (score 991 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2383c mbtB phenyloxazoline synthase 997 991 ctx neighborhood:544 coexpression:982 textmining:696
Rv0555 menD bifunctional 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase/2-oxoglutarate decarboxylase 995 962 database:900 textmining:888
Rv2386c mbtI salicylate synthase 942 929 database:900
Rv2384 mbtA 2,3-dihydroxybenzoate-AMP ligase 947 926 ctx cooccurence:404 coexpression:854
Rv2540c aroF chorismate synthase 935 910 ctx cooccurence:548 database:800
Rv2949c chorismate pyruvate-lyase 910 901 database:900
Rv0013 trpG anthranilate synthase component II 897 894 ctx fusion:587 cooccurence:745
Rv3214 gpm2 phosphoglycerate mutase 888 882 ctx neighborhood:881
Rv1885c chorismate mutase 906 871 database:800
Rv0948c chorismate mutase 887 870 database:800
Rv2552c aroE shikimate 5-dehydrogenase 880 862 database:800
Rv1609 trpE anthranilate synthase component I 866 854 database:800
Rv3800c pks13 polyketide synthase 864 809 coexpression:782
Rv3772 hisC2 histidinol-phosphate aminotransferase 812 805 database:800
Rv2231c cobC aminotransferase 810 804 database:800

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: isochorismate synthase
  • MTBC0 PGAP product: isochorismate synthase
  • Pfam (hmmscan --cut_ga): Chorismate_bind PF00425.25 (E=8e-71)
  • (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_217731.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Chorismate_bind (PF00425.25)
  • 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 COG1169
  • Curated reference: UniProt P9WFW9 (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 — 49 functional partner(s); context anchor mbtB
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003421|Rv3215|entC
MSAHVATLHPEPPFALCGPRGTLIARGVRTRYCDVRAAQAALRSGTAPILLGALPFDVSRPAALMVPDGVLRARKLPDWPTGPLPKVRVAAALPPPADYLTRIGRARDLLAAFDGPLHKVVLARAVQLTADAPLDARVLLRRLVVADPTAYGYLVDLTSAGNDDTGAALVGASPELLVARSGNRVMCKPFAGSAPRAADPKLDAANAAALASSAKNRHEHQLVVDTMRVALEPLCEDLTIPAQPQLNRTAAVWHLCTAITGRLRNISTTAIDLALALHPTPAVGGVPTKAATELIAELEGDRGFYAGAVGWCDGRGDGHWVVSIRCAQLSADRRAALAHAGGGIVAESDPDDELEETTTKFATILTALGVEQ