tkt Resolved · high auto-curated

H37Rv Rv1449c · MTBC0 mtbc0_001551 · 700 aa · 1637465–1639567 (-) · RefSeq NP_215965.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)transketolase
MTBC0 PGAP re-annotationtransketolase
Revised (this work)Transketolase. Pfam: Transketolase_N (PF00456.27), Transket_pyr (PF02779.30), Transketolase_C_1 (PF22613.2), Transketolase_C (PF02780.26).

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

Curated reference (UniProt)

UniProt P9WG25 SwissProt · reviewed · Evidence at protein level
UniProt nameTransketolase
EC (curated) EC 2.2.1.1
Curated functionCatalyzes the reversible transfer of a two-carbon ketol group from sedoheptulose-7-phosphate to glyceraldehyde-3-phosphate, producing xylulose-5-phosphate and ribose-5-phosphate. Catalyzes the transfer of a two-carbon ketol group from a ketose donor to an aldose acceptor, via a covalent intermediate with the cofactor thiamine pyrophosphate.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category G Carbohydrate transport and metabolism
Preferred nametkt
eggNOG descriptionCatalyzes the transfer of a two-carbon ketol group from a ketose donor to an aldose acceptor, via a covalent intermediate with the cofactor thiamine pyrophosphate
Orthologous groupCOG0021
EC number EC 2.2.1.1
KEGG orthology K00615
KEGG pathways map00030, map00710, map01051, map01100, map01110, map01120, map01130, map01200, map01230
KEGG modules M00004, M00007, M00165, M00167
Gene Ontology (16) GO:0005575, GO:0005576, GO:0005618, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0005886, GO:0008150, GO:0016020, GO:0030312, GO:0040007 +4 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 0.293 · purifying
Polymorphic sites (≥ 0.1% of strains) 14 synonymous, 12 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
Transketolase_NPF00456.27 3.1e-14323–358 Transketolase, thiamine diphosphate binding domain
Transket_pyrPF02779.30 9.2e-53374–555 Transketolase, pyrimidine binding domain
Transketolase_C_1PF22613.2 2.9e-38569–686 Transketolase-like TK C-terminal domain
Transketolase_CPF02780.26 8.8e-13583–690 Transketolase, C-terminal domain

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

Closest characterised functional partner: tal (transaldolase), high confidence from genomic context alone (score 999 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1448c tal transaldolase 999 999 ctx neighborhood:865 coexpression:859 database:900 textmining:745
Rv0946c pgi glucose-6-phosphate isomerase 988 974 coexpression:675 database:900 textmining:564
Rv1408 rpe ribulose-phosphate 3-epimerase 991 973 coexpression:408 database:900 textmining:719
Rv1447c zwf2 glucose-6-phosphate 1-dehydrogenase 982 949 ctx neighborhood:865 coexpression:439 textmining:674
Rv0363c fba fructose-bisphosphate aldolase 973 948 coexpression:461 database:900 textmining:511
Rv1099c glpX fructose 1,6-bisphosphatase 974 945 ctx fusion:418 database:900 textmining:562
Rv1023 eno enolase 967 945 coexpression:642 database:800 textmining:434
Rv1017c prsA ribose-phosphate pyrophosphokinase 964 944 coexpression:463 database:900
Rv1617 pykA pyruvate kinase 969 939 coexpression:646 database:800 textmining:525
Rv3068c pgmA phosphoglucomutase PgmA 954 938 database:900
Rv1436 gap glyceraldehyde 3-phosphate dehydrogenase 960 934 coexpression:564 database:800 textmining:429
Rv2436 rbsK ribokinase RbsK 937 929 database:900
Rv0478 deoC 2-deoxyribose-5-phosphate aldolase 938 920 database:900
Rv2465c rpiB ribose-5-phosphate isomerase B 959 913 database:900 textmining:549
Rv3010c pfkA 6-phosphofructokinase 949 911 database:900 textmining:453

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: transketolase
  • MTBC0 PGAP product: transketolase
  • Pfam (hmmscan --cut_ga): Transketolase_N PF00456.27 (E=3e-143), Transket_pyr PF02779.30 (E=9e-53), Transketolase_C_1 PF22613.2 (E=3e-38), Transketolase_C PF02780.26 (E=9e-13)
  • (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_215965.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Transketolase_N (PF00456.27), Transket_pyr (PF02779.30), Transketolase_C_1 (PF22613.2), Transketolase_C (PF02780.26)
  • 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 COG0021
  • Curated reference: UniProt P9WG25 (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 — 161 functional partner(s); context anchor tal
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001551|Rv1449c|tkt
MTTLEEISALTRPRHPDDWTEIDSAAVDTIRVLAADAVQKVGNGHPGTAMSLAPLAYTLFQRTMRHDPSDTHWLGRDRFVLSAGHSSLTLYIQLYLGGFGLELSDIESLRTWGSKTPGHPEFRHTPGVEITTGPLGQGLASAVGMAMASRYERGLFDPDAEPGASPFDHYIYVIASDGDIEEGVTSEASSLAAVQQLGNLIVFYDRNQISIEDDTNIALCEDTAARYRAYGWHVQEVEGGENVVGIEEAIANAQAVTDRPSFIALRTVIGYPAPNLMDTGKAHGAALGDDEVAAVKKIVGFDPDKTFQVREDVLTHTRGLVARGKQAHERWQLEFDAWARREPERKALLDRLLAQKLPDGWDADLPHWEPGSKALATRAASGAVLSALGPKLPELWGGSADLAGSNNTTIKGADSFGPPSISTKEYTAHWYGRTLHFGVREHAMGAILSGIVLHGPTRAYGGTFLQFSDYMRPAVRLAALMDIDTIYVWTHDSIGLGEDGPTHQPIEHLSALRAIPRLSVVRPADANETAYAWRTILARRNGSGPVGLILTRQGVPVLDGTDAEGVARGGYVLSDAGGLQPGEEPDVILIATGSEVQLAVAAQTLLADNDILARVVSMPCLEWFEAQPYEYRDAVLPPTVSARVAVEAGVAQCWHQLVGDTGEIVSIEHYGESADHKTLFREYGFTAEAVAAAAERALDN