folD Resolved · high auto-curated

H37Rv Rv3356c · MTBC0 - · 281 aa · 3769804–3770649 (-) · RefSeq NP_217873.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)bifunctional methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase
MTBC0 PGAP re-annotation
Revised (this work)Bifunctional methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase. Pfam: THF_DHG_CYH (PF00763.29), THF_DHG_CYH_C (PF02882.26).

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

Annotated on the H37Rv protein: this gene has no 1:1 ancestral MTBC0 anchor (PE/PPE, paralogue, IS element, or otherwise unanchored CDS).

Curated reference (UniProt)

UniProt P9WG81 SwissProt · reviewed · Evidence at protein level
UniProt nameBifunctional protein FolD [Includes: Methylenetetrahydrofolate dehydrogenase
EC (curated) EC 1.5.1.5, EC 3.5.4.9
Curated functionCatalyzes the oxidation of 5,10-methylenetetrahydrofolate to 5,10-methenyltetrahydrofolate and then the hydrolysis of 5,10-methenyltetrahydrofolate to 10-formyltetrahydrofolate.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category F Nucleotide transport and metabolism
Preferred namefolD
eggNOG descriptionCatalyzes the oxidation of 5,10- methylenetetrahydrofolate to 5,10-methenyltetrahydrofolate and then the hydrolysis of 5,10-methenyltetrahydrofolate to 10- formyltetrahydrofolate
Orthologous groupCOG0190
EC number EC 1.5.1.5, EC 3.5.4.9
KEGG orthology K01491
KEGG pathways map00670, map00720, map01100, map01120, map01200
KEGG modules M00140, M00377
Gene Ontology (31) GO:0003674, GO:0003824, GO:0004477, GO:0004488, GO:0005575, GO:0005576, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0005886, GO:0006730 +19 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 0.563 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 3 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
THF_DHG_CYHPF00763.29 7.5e-376–120 Tetrahydrofolate dehydrogenase/cyclohydrolase, catalytic domain
THF_DHG_CYH_CPF02882.26 1.5e-52139–280 Tetrahydrofolate dehydrogenase/cyclohydrolase, NAD(P)-binding domain

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

Closest characterised functional partner: Rv3355c (integral membrane protein), high confidence from genomic context alone (score 882 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0070c glyA2 serine hydroxymethyltransferase 982 971 coexpression:647 database:900 textmining:415
Rv1093 glyA1 serine hydroxymethyltransferase 982 971 coexpression:651 database:900 textmining:415
Rv0957 purH bifunctional phosphoribosylaminoimidazolecarboxamide formyltransferase/inosinemonophosphate cyclohydrolase 994 969 coexpression:648 database:900 textmining:845
Rv0956 purN phosphoribosylglycinamide formyltransferase PurN 995 962 coexpression:425 database:900 textmining:895
Rv2211c gcvT aminomethyltransferase 960 948 coexpression:460 database:900
Rv1406 fmt methionyl-tRNA formyltransferase 961 947 coexpression:461 database:900
Rv2964 purU formyltetrahydrofolate deformylase 974 941 database:900 textmining:593
Rv2764c thyA thymidylate synthase ThyA 965 924 database:900 textmining:565
Rv2754c thyX thymidylate synthase ThyX 948 908 database:900 textmining:458
Rv0992c 5-formyltetrahydrofolate cyclo-ligase 929 908 database:900
Rv0389 purT phosphoribosylglycinamide formyltransferase PurT 906 900 database:900
Rv3355c integral membrane protein 882 882 ctx neighborhood:881
Rv1832 gcvB glycine dehydrogenase 900 831 coexpression:492 database:500 textmining:435
Rv0777 purB adenylosuccinate lyase PurB 819 783 coexpression:770
Rv3359 oxidoreductase 754 739 ctx neighborhood:738

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

  • Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): bifunctional methylenetetrahydrofolate dehydrogenase/methenyltetrahydrofolate cyclohydrolase
  • Pfam (hmmscan --cut_ga): THF_DHG_CYH PF00763.29 (E=8e-37), THF_DHG_CYH_C PF02882.26 (E=2e-52)
  • (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_217873.1)
  • Domains: Pfam-A via hmmscan --cut_ga — THF_DHG_CYH (PF00763.29), THF_DHG_CYH_C (PF02882.26)
  • 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 COG0190
  • Curated reference: UniProt P9WG81 (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 — 84 functional partner(s); context anchor Rv3355c
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv3356c|folD
MGAIMLDGKATRDEIFGDLKQRVAALDAAGRTPGLGTILVGDDPGSQAYVRGKHADCAKVGITSIRRDLPADISTATLNETIDELNANPDCTGYIVQLPLPKHLDENAALERVDPAKDADGLHPTNLGRLVLGTPAPLPCTPRGIVHLLRRYDISIAGAHVVVIGRGVTVGRPLGLLLTRRSENATVTLCHTGTRDLPALTRQADIVVAAVGVAHLLTADMVRPGAAVIDVGVSRTDDGLVGDVHPDVWELAGHVSPNPGGVGPLTRAFLLTNVVELAERR