aftA Resolved · high auto-curated
H37Rv Rv3792 · MTBC0 mtbc0_004020 ·
643 aa · 4262053–4263984 (+) ·
RefSeq NP_218309.1
Annotation: from legacy to revised
| Legacy (H37Rv / Mycobrowser) | arabinofuranosyltransferase |
|---|---|
| MTBC0 PGAP re-annotation | galactan 5-O-arabinofuranosyltransferase |
| Revised (this work) | Galactan 5-O-arabinofuranosyltransferase. Pfam: AftA_N (PF12250.15), AftA_C (PF12249.14). |
Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.
Curated reference (UniProt)
| UniProt |
P9WN03
SwissProt · reviewed
· Evidence at protein level
|
|---|---|
| UniProt name | Galactan 5-O-arabinofuranosyltransferase |
| EC (curated) |
EC 2.4.2.46
|
| Curated function | Involved in the biosynthesis of the arabinogalactan (AG) region of the mycolylarabinogalactan-peptidoglycan (mAGP) complex, an essential component of the mycobacterial cell wall. Catalyzes the addition of the first key arabinofuranosyl (Araf) residue from the sugar donor decaprenyl-phospho-arabinose (DPA) on the C-5 of a 6-linked galactofuranosyl (Galf) of the galactan domain, thus 'priming' the galactan for further elaboration by other arabinofuranosyltransferases. It is not able to add an Araf residue to a terminal Galf. |
Functional vocabulary (eggNOG-mapper, orthology transfer)
| COG category |
M Cell wall / membrane / envelope biogenesis
|
|---|---|
| Preferred name | aftA |
| eggNOG description | Involved in the biosynthesis of the arabinogalactan (AG) region of the mycolylarabinogalactan-peptidoglycan (mAGP) complex, an essential component of the mycobacterial cell wall. Catalyzes the addition of the first key arabinofuranosyl (Araf) residue from the sugar donor decaprenyl-phospho-arabinose (DPA) on the C-5 of a 6-linked galactofuranosyl (Galf) of the galactan domain, thus 'priming' the galactan for further elaboration by other arabinofuranosyltransferases |
| Orthologous group | 28MYD |
| EC number |
EC 2.4.2.46
|
| KEGG orthology |
K13686
|
| CAZy family |
GT85
|
| Gene Ontology (43) |
GO:0003674, GO:0003824, GO:0005575, GO:0005618, GO:0005623, GO:0005886, GO:0008150, GO:0008152, GO:0008194, GO:0008378, GO:0009058, GO:0009059 +31 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 | 0.451 · purifying |
|---|---|
| Polymorphic sites (≥ 0.1% of strains) | 10 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)
| Pfam | Accession | i-Evalue | Residues | Description |
|---|---|---|---|---|
AftA_N | PF12250.15 | 1.8e-165 | 31–437 | Arabinofuranosyltransferase N terminal |
AftA_C | PF12249.14 | 1.4e-74 | 465–637 | Arabinofuranosyltransferase A C terminal |
Functional interaction network (STRING v12, guilt-by-association)
Closest characterised functional partner: embC (arabinosyltransferase C), high confidence from genomic context alone (score 983 excluding text-mining).
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv3793 embC |
arabinosyltransferase C | 998 | 983 ctx | neighborhood:881 cooccurence:754 coexpression:474 textmining:922 |
Rv3794 embA |
arabinosyltransferase A | 997 | 959 ctx | neighborhood:669 cooccurence:760 database:500 textmining:931 |
Rv3795 embB |
arabinosyltransferase B | 995 | 953 ctx | neighborhood:580 cooccurence:755 database:500 textmining:900 |
Rv3791 dprE2 |
decaprenylphosphoryl-D-2-keto erythropentose reductase | 957 | 905 ctx | neighborhood:881 textmining:573 |
Rv3790 dprE1 |
decaprenylphosphoryl-beta-D-ribose oxidase | 933 | 904 ctx | neighborhood:881 |
Rv3789 |
GtrA family protein | 911 | 886 ctx | neighborhood:823 |
Rv3035 hyp |
hypothetical protein | 769 | 769 ctx | cooccurence:766 |
Rv3802c |
membrane protein | 755 | 756 ctx | cooccurence:755 |
Rv3805c aftB |
terminal beta-(1->2)-arabinofuranosyltransferase | 982 | 752 ctx | cooccurence:743 textmining:933 |
Rv2673 aftC |
alpha-(1->3)-arabinofuranosyltransferase | 973 | 744 ctx | cooccurence:740 textmining:903 |
Rv3788 hyp |
hypothetical protein | 733 | 734 ctx | neighborhood:732 |
Rv1100 hyp |
hypothetical protein | 733 | 733 ctx | cooccurence:733 |
Rv1476 |
membrane protein | 719 | 720 ctx | cooccurence:719 |
Rv1610 |
membrane protein | 673 | 674 ctx | cooccurence:669 |
Rv0358 hyp |
hypothetical protein | 669 | 670 ctx | cooccurence:665 |
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: arabinofuranosyltransferase
- MTBC0 PGAP product: galactan 5-O-arabinofuranosyltransferase
- Pfam (hmmscan --cut_ga): AftA_N PF12250.15 (E=2e-165), AftA_C PF12249.14 (E=1e-74)
- (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_218309.1)
- Domains: Pfam-A via hmmscan --cut_ga — AftA_N (PF12250.15), AftA_C (PF12249.14)
- 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
28MYD - Curated reference: UniProt P9WN03 (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 —
75 functional partner(s); context anchor
embC - Primary literature: none located yet; annotation rests on the domain/homology sources above.
Ancestral MTBC0 protein sequence
>mtbc0_004020|Rv3792|aftA MPSRRKSPQFGHEMGAFTSARAREVLVALGQLAAAVVVAVGVAVVSLLAIARVEWPAFPSSNQLHALTTVGQVGCLAGLVGIGWLWRHGRFRRLARLGGLVLVSAFTVVTLGMPLGATKLYLFGISVDQQFRTEYLTRLTDTAALRDMTYIGLPPFYPPGWFWIGGRAAALTGTPAWEMFKPWAITSMAIAVAVALVLWWRMIRFEYALLVTVATAAVMLAYSSPEPYAAMITVLLPPMLVLTWSGLGARDRQGWAAVVGAGVFLGFAATWYTLLVAYGAFTVVLMALLLAGSRLQSGIKAAVDPLCRLAVVGAIAAAIGSTTWLPYLLRAARDPVSDTGSAQHYLPADGAALTFPMLQFSLLGAICLLGTLWLVMRARSSAPAGALAIGVLAVYLWSLLSMLATLARTTLLSFRLQPTLSVLLVAAGAFGFVEAVQALGKRGRGVIPMAAAIGLAGAIAFSQDIPDVLRPDLTIAYTDTDGYGQRGDRRPPGSEKYYPAIDAAIRRVTGKRRDRTVVLTADYSFLSYYPYWGFQGLTPHYANPLAQFDKRATQIDSWSGLSTADEFIAALDKLPWQPPTVFLMRHGAHNSYTLRLAQDVYPNQPNVRRYTVDLRTALFADPRFVVEDIGPFVLAIRKPQESA