mgtA Resolved · high auto-curated

H37Rv Rv0557 · MTBC0 - · 378 aa · 648536–649672 (+) · RefSeq NP_215071.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)GDP-mannose-dependent alpha-mannosyltransferase
MTBC0 PGAP re-annotation
Revised (this work)GDP-mannose-dependent alpha-mannosyltransferase. Pfam: Glyco_transf_4 (PF13439.13), Glyco_trans_4_4 (PF13579.13), Glycos_transf_1 (PF00534.27), Glyco_trans_1_4 (PF13692.13).

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 P9WMY5 SwissProt · reviewed · Evidence at protein level
UniProt nameGDP-mannose-dependent alpha-mannosyltransferase
EC (curated) EC 2.4.1.-
Curated functionCatalyzes the addition of a mannose residue from GDP-D-mannose to GlcAGroAc2 to generate 1,2-di-O-C16/C18:1-(alpha-D-mannopyranosyl)-(1-4)-(alpha-D-glucopyranosyluronic acid)-(1-3)-glycerol(ManGlcAGroAc2).

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category M Cell wall / membrane / envelope biogenesis
Preferred namemgtA
eggNOG descriptionPFAM Glycosyl transferase, group 1
Orthologous groupCOG0438
KEGG orthology K12583
CAZy family GT4
Gene Ontology (28) GO:0000030, GO:0003674, GO:0003824, GO:0006629, GO:0006643, GO:0006664, GO:0008150, GO:0008152, GO:0008610, GO:0009058, GO:0009247, GO:0009987 +16 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 0.756 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 4 synonymous, 8 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
Glyco_transf_4PF13439.13 1.3e-3017–187 Glycosyltransferase Family 4
Glyco_trans_4_4PF13579.13 6.1e-2318–176 Glycosyl transferase 4-like domain
Glycos_transf_1PF00534.27 4.3e-22202–340 Glycosyl transferases group 1
Glyco_trans_1_4PF13692.13 3.2e-21207–336 Glycosyl transferases group 1

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

Closest characterised functional partner: menH (demethylmenaquinone methyltransferase), high confidence from genomic context alone (score 861 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv0558 menH demethylmenaquinone methyltransferase 866 861 ctx neighborhood:861
Rv0555 menD bifunctional 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase/2-oxoglutarate decarboxylase 888 800 ctx neighborhood:800 textmining:468
Rv0556 transmembrane protein 799 800 ctx neighborhood:800
Rv1326c glgB 1,4-alpha-glucan branching protein 818 781 coexpression:407 database:572
Rv1562c treZ malto-oligosyltrehalose trehalohydrolase 805 781 coexpression:407 database:572
Rv0553 menC muconate cycloisomerase 756 756 ctx neighborhood:756
Rv0552 hyp hypothetical protein 761 749 ctx neighborhood:749
Rv0554 bpoC non-heme bromoperoxidase BpoC 711 712 ctx neighborhood:705
Rv2529 hyp hypothetical protein 673 661 database:516
Rv0322 udgA UDP-glucose 6-dehydrogenase UdgA 824 583 coexpression:442 textmining:596
Rv1510 hyp hypothetical protein 575 548 coexpression:420
Rv2307c hyp hypothetical protein 568 548 experimental:443
Rv3630 integral membrane protein 556 534 coexpression:414
Rv3809c glf UDP-galactopyranose mutase 575 487 coexpression:470
Rv1328 glgP glycogen phosphorylase 521 478

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): GDP-mannose-dependent alpha-mannosyltransferase
  • Pfam (hmmscan --cut_ga): Glyco_transf_4 PF13439.13 (E=1e-30), Glyco_trans_4_4 PF13579.13 (E=6e-23), Glycos_transf_1 PF00534.27 (E=4e-22), Glyco_trans_1_4 PF13692.13 (E=3e-21)
  • (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_215071.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Glyco_transf_4 (PF13439.13), Glyco_trans_4_4 (PF13579.13), Glycos_transf_1 (PF00534.27), Glyco_trans_1_4 (PF13692.13)
  • 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 COG0438
  • Curated reference: UniProt P9WMY5 (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 — 48 functional partner(s); context anchor menH
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv0557|mgtA
MCGVRVAIVAESFLPQVNGVSNSVVKVLEHLRRTGHEALVIAPDTPPGEDRAERLHDGVRVHRVPSRMFPKVTTLPLGVPTFRMLRALRGFDPDVVHLASPALLGYGGLHAARRLGVPTVAVYQTDVPGFASSYGIPMTARAAWAWFRHLHRLADRTLAPSTATMESLIAQGIPRVHRWARGVDVQRFAPSARNEVLRRRWSPDGKPIVGFVGRLAPEKHVDRLTGLAASGAVRLVIVGDGIDRARLQSAMPTAVFTGARYGKELAEAYASMDVFVHSGEHETFCQVVQEALASGLPVIAPDAGGPRDLITPHRTGLLLPVGEFEHRLPDAVAHLVHERQRYALAARRSVLGRSWPVVCDELLGHYEAVRGRRTTQAA