glfT2 Resolved · high auto-curated

H37Rv Rv3808c · MTBC0 mtbc0_004036 · 637 aa · 4294476–4296389 (-) · RefSeq NP_218325.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)galactofuranosyl transferase GlfT
MTBC0 PGAP re-annotationgalactofuranosyl transferase GlfT2
Revised (this work)Galactofuranosyl transferase GlfT2. Pfam: Glft2_N (PF17994.8), Glyco_tranf_2_3 (PF13641.13), GlfT2_domain3 (PF19320.5).

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

Curated reference (UniProt)

UniProt O53585 SwissProt · reviewed · Evidence at protein level
UniProt nameGalactofuranosyltransferase GlfT2
EC (curated) EC 2.4.1.288
Curated functionInvolved in the galactan polymerization of the arabinogalactan (AG) region of the mycolylarabinogalactan-peptidoglycan (mAGP) complex, an essential component of the mycobacteria cell wall. Thus, successively transfers approximately 28 galactofuranosyl (Galf) residues from UDP-galactofuranose (UDP-Galf) onto the galactofuranosyl-galactofuranosyl-rhamnosyl-GlcNAc-diphospho-decaprenol (Galf-Galf-Rha-GlcNAc-PP-C50) acceptor produced by GlfT1, with alternating 1->5 and 1->6 links, forming a galactan domain with approximately 30 galactofuranosyl residues.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
Preferred nameglfT
eggNOG descriptiontransferase
Orthologous groupCOG1216
EC number EC 2.4.1.288
KEGG orthology K16650
CAZy family GT2
Gene Ontology (78) GO:0000271, GO:0003674, GO:0003824, GO:0005575, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0005886, GO:0005975, GO:0005976, GO:0006139 +66 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 0.481 · purifying
Polymorphic sites (≥ 0.1% of strains) 4 synonymous, 6 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
Glft2_NPF17994.8 4.7e-619–152 Galactofuranosyltransferase 2 N-terminal
Glyco_tranf_2_3PF13641.13 9.4e-19161–418 Glycosyltransferase like family 2
GlfT2_domain3PF19320.5 3.2e-84435–626 Galactofuranosyltransferase-2, domain 3

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

Closest characterised functional partner: glfT1 (galactofuranosyl transferase GlfT), high confidence from genomic context alone (score 980 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3782 glfT1 galactofuranosyl transferase GlfT 998 980 ctx cooccurence:770 database:900 textmining:934
Rv3809c glf UDP-galactopyranose mutase 991 976 ctx neighborhood:881 cooccurence:762 textmining:676
Rv3806c ubiA decaprenyl-phosphate phosphoribosyltransferase 970 963 ctx neighborhood:843 coexpression:772
Rv3807c decaprenylphosphoryl-5-phosphoribose phosphatase 898 860 ctx neighborhood:843
Rv3805c aftB terminal beta-(1->2)-arabinofuranosyltransferase 857 832 ctx neighborhood:756
Rv1836c hyp hypothetical protein 739 740 coexpression:740
Rv3792 aftA arabinofuranosyltransferase 876 618 database:500 textmining:691
Rv3783 rfbD O-antigen/lipopolysaccharide ABC transporter permease RfbD 924 613 textmining:813
Rv3802c membrane protein 617 597
Rv2518c ldtB L,D-transpeptidase LdtB 521 522 ctx cooccurence:520
Rv3794 embA arabinosyltransferase A 681 476 ctx cooccurence:450 textmining:416
Rv3810 pirG cell surface protein 471 471 ctx neighborhood:459
Rv3804c fbpA diacylglycerol acyltransferase/mycolyltransferase Ag85A 470 470
Rv3811 hyp hypothetical protein 466 466
Rv3795 embB arabinosyltransferase B 570 465 ctx cooccurence:445

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: galactofuranosyl transferase GlfT
  • MTBC0 PGAP product: galactofuranosyl transferase GlfT2
  • Pfam (hmmscan --cut_ga): Glft2_N PF17994.8 (E=5e-61), Glyco_tranf_2_3 PF13641.13 (E=9e-19), GlfT2_domain3 PF19320.5 (E=3e-84)
  • (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_218325.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Glft2_N (PF17994.8), Glyco_tranf_2_3 (PF13641.13), GlfT2_domain3 (PF19320.5)
  • 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 COG1216
  • Curated reference: UniProt O53585 (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 — 35 functional partner(s); context anchor glfT1
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_004036|Rv3808c|glfT2
MSELAASLLSRVILPRPGEPLDVRKLYLEESTTNARRAHAPTRTSLQIGAESEVSFATYFNAFPASYWRRWTTCKSVVLRVQVTGAGRVDVYRTKATGARIFVEGHDFTGTEDQPAAVETEVVLQPFEDGGWVWFDITTDTAVTLHSGGWYATSPAPGTANIAVGIPTFNRPADCVNALRELTADPLVDQVIGAVIVPDQGERKVRDHPDFPAAAARLGSRLSIHDQPNLGGSGGYSRVMYEALKNTDCQQILFMDDDIRLEPDSILRVLAMHRFAKAPMLVGGQMLNLQEPSHLHIMGEVVDRSIFMWTAAPHAEYDHDFAEYPLNDNNSRSKLLHRRIDVDYNGWWTCMIPRQVAEELGQPLPLFIKWDDADYGLRAAEHGYPTVTLPGAAIWHMAWSDKDDAIDWQAYFHLRNRLVVAAMHWDGPKAQVIGLVRSHLKATLKHLACLEYSTVAIQNKAIDDFLAGPEHIFSILESALPQVHRIRKSYPDAVVLPAASELPPPLHKNKAMKPPVNPLVIGYRLARGIMHNLTAANPQHHRRPEFNVPTQDARWFLLCTVDGATVTTADGCGVVYRQRDRAKMFALLWQSLRRQRQLLKRFEEMRRIYRDALPTLSSKQKWETALLPAANQEPEHG