folB Resolved · high auto-curated

H37Rv Rv3607c · MTBC0 - · 133 aa · 4048744–4049145 (-) · RefSeq YP_177996.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)dihydroneopterin aldolase
MTBC0 PGAP re-annotation
Revised (this work)Dihydroneopterin aldolase. Pfam: FolB (PF02152.24).

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 P9WNC5 SwissProt · reviewed · Evidence at protein level
UniProt nameDihydroneopterin aldolase
EC (curated) EC 1.13.11.81, EC 4.1.2.25, EC 5.1.99.8
Curated functionPossible cargo protein of a type 1 encapsulin nanocompartment involved in protection against oxidative stress (Probable). Catalyzes the conversion of 7,8-dihydroneopterin to 6-hydroxymethyl-7,8-dihydropterin, 7,8-dihydromonapterin and 7,8-dihydroxanthopterin, respectively, in equal quantities. After longer incubation times the only product is 6-hydroxymethyl-7,8-dihydropterin. Retains aldolase activity when encapsulated with a slight decrease in rate. It is not known if this protein is normally found in the encapsulin nanocompartment.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category H Coenzyme transport and metabolism
Preferred namefolB
eggNOG descriptionCatalyzes the conversion of 7,8-dihydroneopterin to 6- hydroxymethyl-7,8-dihydropterin
Orthologous groupCOG1539
EC number EC 1.13.11.81, EC 2.7.6.3, EC 4.1.2.25, EC 5.1.99.8
KEGG orthology K01633, K13940
KEGG pathways map00790, map01100
KEGG modules M00126, M00840
Gene Ontology (2) GO:0008150, GO:0040007

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 0.178 · strong purifying
Polymorphic sites (≥ 0.1% of strains) 2 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
FolBPF02152.24 2.2e-385–116 Dihydroneopterin aldolase

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

Closest characterised functional partner: folP1 (dihydropteroate synthase), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3608c folP1 dihydropteroate synthase 999 1000 ctx neighborhood:882 cooccurence:455 coexpression:947 database:900 textmining:819
Rv3606c folK 2-amino-4-hydroxy-6-hydroxymethyldihydropteridinepyrophosphokinase 999 1000 ctx neighborhood:882 fusion:864 cooccurence:712 coexpression:974 database:900 textmining:718
Rv3609c folE GTP cyclohydrolase I 999 998 ctx neighborhood:881 cooccurence:489 coexpression:967 textmining:862
Rv1207 folP2 dihydropteroate synthase 992 986 ctx cooccurence:470 coexpression:735 database:900 textmining:497
Rv3610c ftsH zinc metalloprotease FtsH 963 962 ctx neighborhood:867 coexpression:729
Rv3605c hyp hypothetical protein 882 882 ctx neighborhood:882
Rv3604c transmembrane protein 738 738 ctx neighborhood:734
Rv3602c panC pantothenate synthetase 746 663 ctx neighborhood:661
Rv3601c panD aspartate 1-decarboxylase 677 663 ctx neighborhood:661
Rv3600c coaX type III pantothenate kinase 663 663 ctx neighborhood:661
Rv3603c hyp hypothetical protein 661 661 ctx neighborhood:661
Rv3598c lysS lysine--tRNA ligase 633 633 ctx neighborhood:633
Rv3597c lsr2 iron-regulated H-NS-like protein 596 596 ctx neighborhood:593
Rv3611 Rv3611, (MTCY07H7B.11c), len: 217 aa. Hypothetical unknown arg-, pro-rich protein. Possible ORF containing several direct repeats. 545 545 ctx neighborhood:544
Rv1341 rdgB non-canonical purine NTP pyrophosphatase 528 501 coexpression: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

  • Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): dihydroneopterin aldolase
  • Pfam (hmmscan --cut_ga): FolB PF02152.24 (E=2e-38)
  • (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 YP_177996.1)
  • Domains: Pfam-A via hmmscan --cut_ga — FolB (PF02152.24)
  • 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 COG1539
  • Curated reference: UniProt P9WNC5 (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 — 36 functional partner(s); context anchor folP1
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv3607c|folB
MADRIELRGLTVHGRHGVYDHERVAGQRFVIDVTVWIDLAEAANSDDLADTYDYVRLASRAAEIVAGPPRKLIETVGAEIADHVMDDQRVHAVEVAVHKPQAPIPQTFDDVAVVIRRSRRGGRGWVVPAGGAV