thiC Resolved · high auto-curated

H37Rv Rv0423c · MTBC0 mtbc0_000444 · 547 aa · 511947–513590 (-) · RefSeq NP_214937.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)phosphomethylpyrimidine synthase
MTBC0 PGAP re-annotationphosphomethylpyrimidine synthase ThiC
Revised (this work)Phosphomethylpyrimidine synthase ThiC. Pfam: ThiC-associated (PF13667.12), ThiC_Rad_SAM (PF01964.25).

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

Curated reference (UniProt)

UniProt P9WG79 SwissProt · reviewed · Evidence at protein level
UniProt namePhosphomethylpyrimidine synthase
EC (curated) EC 4.1.99.17
Curated functionCatalyzes the synthesis of the hydroxymethylpyrimidine phosphate (HMP-P) moiety of thiamine from aminoimidazole ribotide (AIR) in a radical S-adenosyl-L-methionine (SAM)-dependent reaction.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category H Coenzyme transport and metabolism
Preferred namethiC
eggNOG descriptionCatalyzes the synthesis of the hydroxymethylpyrimidine phosphate (HMP-P) moiety of thiamine from aminoimidazole ribotide (AIR) in a radical S-adenosyl-L-methionine (SAM)-dependent reaction
Orthologous groupCOG0422
EC number EC 4.1.99.17
KEGG orthology K03147
KEGG pathways map00730, map01100
KEGG modules M00127
Gene Ontology (46) GO:0005575, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0005886, GO:0006725, GO:0006766, GO:0006767, GO:0006772, GO:0006790, GO:0006807 +34 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 0.641 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 4 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
ThiC-associatedPF13667.12 2.3e-0815–72 ThiC-associated domain
ThiC_Rad_SAMPF01964.25 1.8e-18782–502 Radical SAM ThiC family

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

Closest characterised functional partner: thiD (hydroxymethylpyrimidine/phosphomethylpyrimidine kinase), high confidence from genomic context alone (score 997 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0422c thiD hydroxymethylpyrimidine/phosphomethylpyrimidine kinase 998 997 ctx neighborhood:846 coexpression:806 database:900
Rv0417 thiG thiazole synthase 941 923 ctx cooccurence:500 coexpression:816
Rv0414c thiE thiamine-phosphate synthase 902 873 coexpression:809
Rv0421c hyp hypothetical protein 848 848 ctx neighborhood:846
Rv0416 thiS sulfur carrier protein ThiS 851 842 coexpression:804
Rv1173 fbiC FO synthase 859 817 coexpression:802
Rv0809 purM phosphoribosylformylglycinamidine cyclo-ligase PurM 814 803 database:800
Rv3276c purK 5-(carboxyamino)imidazole ribonucleotide synthase 801 802 database:800
Rv3116 moeB2 molybdenum cofactor biosynthesis protein MoeB 664 542 coexpression:480
Rv3206c moeB1 adenylyltransferase/sulfurtransferase MoeZ 664 542 coexpression:480
Rv0424c hyp hypothetical protein 518 518 ctx neighborhood:506
Rv1589 bioB biotin synthetase 641 507
Rv2338c moeW molybdopterin biosynthesis protein MoeW 527 492 coexpression:475
Rv1355c moeY molybdopterin biosynthesis protein MoeY 526 492 coexpression:475
Rv2337c hyp hypothetical protein 524 490 coexpression:473

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: phosphomethylpyrimidine synthase
  • MTBC0 PGAP product: phosphomethylpyrimidine synthase ThiC
  • Pfam (hmmscan --cut_ga): ThiC-associated PF13667.12 (E=2e-08), ThiC_Rad_SAM PF01964.25 (E=2e-187)
  • (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_214937.1)
  • Domains: Pfam-A via hmmscan --cut_ga — ThiC-associated (PF13667.12), ThiC_Rad_SAM (PF01964.25)
  • 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 COG0422
  • Curated reference: UniProt P9WG79 (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 — 30 functional partner(s); context anchor thiD
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000444|Rv0423c|thiC
MTITVEPSVTTGPIAGSAKAYREIEAPGSGATLQVPFRRVHLSTGDHFDLYDTSGPYTDTDTVIDLTAGLPHRPGVVRDRGTQLQRARAGEITAEMAFIAAREDMSAELVRDEVARGRAVIPANHHHPESEPMIIGKAFAVKVNANIGNSAVTSSIAEEVDKMVWATRWGADTIMDLSTGKNIHETREWILRNSPVPVGTVPIYQALEKVKGDPTELTWEIYRDTVIEQCEQGVDYMTVHAGVLLRYVPLTAKRVTGIVSRGGSIMAAWCLAHHRESFLYTNFEELCDIFARYDVTFSLGDGLRPGSIADANDAAQFAELRTLGELTKIAKAHGAQVMIEGPGHIPMHKIVENVRLEEELCEEAPFYTLGPLATDIAPAYDHITSAIGAAIIAQAGTAMLCYVTPKEHLGLPDRKDVKDGVIAYKIAAHAADLAKGHPRAQERDDALSTARFEFRWNDQFALSLDPDTAREFHDETLPAEPAKTAHFCSMCGPKFCSMRITQDVREYAAEHGLETEADIEAVLAAGMAEKSREFAEHGNRVYLPITQ