folC Resolved · high auto-curated

H37Rv Rv2447c · MTBC0 mtbc0_002606 · 487 aa · 2770383–2771846 (-) · RefSeq NP_216963.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)folylpolyglutamate synthase FolC
MTBC0 PGAP re-annotationbifunctional tetrahydrofolate synthase/dihydrofolate synthase
Revised (this work)Bifunctional tetrahydrofolate synthase/dihydrofolate synthase. Pfam: Mur_ligase_M (PF08245.19), Mur_ligase_C (PF02875.27).

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

Curated reference (UniProt)

UniProt I6Y0R5 SwissProt · reviewed · Evidence at protein level
UniProt nameDihydrofolate synthase/folylpolyglutamate synthase
EC (curated) EC 6.3.2.12, EC 6.3.2.17
Curated functionCatalyzes the addition of a glutamate residue to dihydropteroate (7,8-dihydropteroate or H2Pte) to form dihydrofolate (7,8-dihydrofolate monoglutamate or H2Pte-Glu). Also catalyzes successive additions of L-glutamate to tetrahydrofolate, leading to folylpolyglutamate derivatives (By similarity)..; FUNCTION: Is involved in the bioactivation of the antituberculous drug para-aminosalicylic acid (PAS). Is able to use hydroxy-dihydropteroate (H2PtePAS) as substrate, which is the product formed by the action of DHPS (FolP1) on PAS, leading to hydroxy-dihydrofolate (H2PtePAS-Glu). This compound inhib.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category H Coenzyme transport and metabolism
Preferred namefolC
eggNOG descriptionFolylpolyglutamate synthase
Orthologous groupCOG0285
EC number EC 6.3.2.12, EC 6.3.2.17
KEGG orthology K11754
KEGG pathways map00790, map01100
KEGG modules M00126, M00841
Gene Ontology (57) GO:0003674, GO:0003824, GO:0004326, GO:0005575, GO:0005622, GO:0005623, GO:0005737, GO:0006082, GO:0006575, GO:0006725, GO:0006732, GO:0006760 +45 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 3.64 · diversifying/relaxed
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 10 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
Mur_ligase_MPF08245.19 3.0e-10158–308 Mur ligase middle domain
Mur_ligase_CPF02875.27 1.4e-15337–448 Mur ligase, glutamate ligase domain

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

Closest characterised functional partner: folP1 (dihydropteroate synthase), high confidence from genomic context alone (score 994 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3608c folP1 dihydropteroate synthase 999 994 ctx fusion:840 coexpression:431 database:900 textmining:924
Rv1207 folP2 dihydropteroate synthase 993 985 ctx fusion:603 coexpression:431 database:900 textmining:603
Rv2448c valS valine--tRNA ligase 959 935 ctx neighborhood:881 coexpression:475 textmining:406
Rv2446c integral membrane protein 967 909 ctx neighborhood:882 textmining:660
Rv2763c dfrA dihydrofolate reductase 991 900 database:900 textmining:922
Rv2764c thyA thymidylate synthase ThyA 985 801 database:800 textmining:929
Rv2445c ndkA nucleoside diphosphate kinase 810 751 ctx neighborhood:708
Rv1093 glyA1 serine hydroxymethyltransferase 658 609 database:500
Rv0070c glyA2 serine hydroxymethyltransferase 654 604 database:500
Rv2449c trans-acting enoyl reductase 603 603 ctx neighborhood:599
Rv3607c folB dihydroneopterin aldolase 919 487 coexpression:445 textmining:850
Rv3609c folE GTP cyclohydrolase I 870 487 coexpression:445 textmining:757
Rv3606c folK 2-amino-4-hydroxy-6-hydroxymethyldihydropteridinepyrophosphokinase 689 487 coexpression:445 textmining:419
Rv3396c guaA GMP synthase 719 467 textmining:496
Rv1341 rdgB non-canonical purine NTP pyrophosphatase 494 461

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: folylpolyglutamate synthase FolC
  • MTBC0 PGAP product: bifunctional tetrahydrofolate synthase/dihydrofolate synthase
  • Pfam (hmmscan --cut_ga): Mur_ligase_M PF08245.19 (E=3e-10), Mur_ligase_C PF02875.27 (E=1e-15)
  • (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_216963.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Mur_ligase_M (PF08245.19), Mur_ligase_C (PF02875.27)
  • 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 COG0285
  • Curated reference: UniProt I6Y0R5 (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 — 64 functional partner(s); context anchor folP1
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_002606|Rv2447c|folC
MNSTNSGPPDSGSATGVVPTPDEIASLLQVEHLLDQRWPETRIDPSLTRISALMDLLGSPQRSYPSIHIAGTNGKTSVARMVDALVTALHRRTGRTTSPHLQSPVERISIDGKPISPAQYVATYREIEPLVALIDQQSQASAGKGGPAMSKFEVLTAMAFAAFADAPVDVAVVEVGMGGRWDATNVINAPVAVITPISIDHVDYLGADIAGIAGEKAGIITRAPDGSPDTVAVIGRQVPKVMEVLLAESVRADASVAREDSEFAVLRRQIAVGGQVLQLQGLGGVYSDIYLPLHGEHQAHNAVLALASVEAFFGAGAQRQLDGDAVRAGFAAVTSPGRLERMRSAPTVFIDAAHNPAGASALAQTLAHEFDFRFLVGVLSVLGDKDVDGILAALEPVFDSVVVTHNGSPRALDVEALALAAGERFGPDRVRTAENLRDAIDVATSLVDDAAADPDVAGDAFSRTGIVITGSVVTAGAARTLFGRDPQ