embB Resolved · high auto-curated

H37Rv Rv3795 · MTBC0 mtbc0_004023 · 1098 aa · 4270635–4273931 (+) · RefSeq NP_218312.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)arabinosyltransferase B
MTBC0 PGAP re-annotationarabinosyltransferase EmbB
Revised (this work)Arabinosyltransferase EmbB. Pfam: Arabino_trans_N (PF17689.9), Arabinose_trans (PF04602.19), Arabino_trans_C (PF14896.13).

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

Curated reference (UniProt)

UniProt P9WNL7 SwissProt · reviewed · Evidence at protein level
UniProt nameProbable arabinosyltransferase B
EC (curated) EC 2.4.2.-
Curated functionArabinosyl transferase responsible for the polymerization of arabinose into the arabinan of arabinogalactan.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category M Cell wall / membrane / envelope biogenesis
Preferred nameembB
eggNOG descriptionCell wall arabinan synthesis protein
Orthologous groupCOG1807
KEGG orthology K11386, K11387
Gene Ontology (10) GO:0005575, GO:0005618, GO:0005623, GO:0005886, GO:0008150, GO:0016020, GO:0030312, GO:0040007, GO:0044464, GO:0071944

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 0.87 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 13 synonymous, 31 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
Arabino_trans_NPF17689.9 8.0e-5451–209 Arabinosyltransferase concanavalin like domain
Arabinose_transPF04602.19 2.4e-195214–688 Mycobacterial cell wall arabinan synthesis protein
Arabino_trans_CPF14896.13 3.4e-134719–1095 EmbC C-terminal domain

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

Closest characterised functional partner: embA (arabinosyltransferase A), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3794 embA arabinosyltransferase A 999 1000 ctx neighborhood:881 coexpression:798 experimental:999 database:900
Rv2244 acpM meromycolate extension acyl carrier protein 999 999 experimental:999
Rv3792 aftA arabinofuranosyltransferase 995 953 ctx neighborhood:580 cooccurence:755 database:500 textmining:900
Rv3791 dprE2 decaprenylphosphoryl-D-2-keto erythropentose reductase 913 887 ctx neighborhood:580 cooccurence:493 database:500
Rv2673 aftC alpha-(1->3)-arabinofuranosyltransferase 947 882 ctx cooccurence:765 database:500 textmining:568
Rv3789 GtrA family protein 874 860 ctx neighborhood:503 cooccurence:726
Rv3802c membrane protein 805 806 ctx cooccurence:771
Rv3805c aftB terminal beta-(1->2)-arabinofuranosyltransferase 948 797 ctx cooccurence:758 textmining:757
Rv3790 dprE1 decaprenylphosphoryl-beta-D-ribose oxidase 852 788 ctx neighborhood:580 cooccurence:493
Rv3244c lpqB lipoprotein LpqB 753 754 ctx cooccurence:750
Rv1476 membrane protein 751 752 ctx cooccurence:750
Rv3438 hyp hypothetical protein 742 742 ctx cooccurence:735
Rv0996 transmembrane protein 734 735 ctx cooccurence:734
Rv0358 hyp hypothetical protein 729 730 ctx cooccurence:728
Rv3793 embC arabinosyltransferase C 751 727 ctx neighborhood:612

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: arabinosyltransferase B
  • MTBC0 PGAP product: arabinosyltransferase EmbB
  • Pfam (hmmscan --cut_ga): Arabino_trans_N PF17689.9 (E=8e-54), Arabinose_trans PF04602.19 (E=2e-195), Arabino_trans_C PF14896.13 (E=3e-134)
  • (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_218312.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Arabino_trans_N (PF17689.9), Arabinose_trans (PF04602.19), Arabino_trans_C (PF14896.13)
  • 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 COG1807
  • Curated reference: UniProt P9WNL7 (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 — 120 functional partner(s); context anchor embA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_004023|Rv3795|embB
MTQCASRRKSTPNRAILGAFASARGTRWVATIAGLIGFVLSVATPLLPVVQTTAMLDWPQRGQLGSVTAPLISLTPVDFTATVPCDVVRAMPPAGGVVLGTAPKQGKDANLQALFVVVSAQRVDVTDRNVVILSVPREQVTSPQCQRIEVTSTHAGTFANFVGLKDPSGAPLRSGFPDPNLRPQIVGVFTDLTGPAPPGLAVSATIDTRFSTRPTTLKLLAIIGAIVATVVALIALWRLDQLDGRGSIAQLLLRPFRPASSPGGMRRLIPASWRTFTLTDAVVIFGFLLWHVIGANSSDDGYILGMARVADHAGYMSNYFRWFGSPEDPFGWYYNLLALMTHVSDASLWMRLPDLAAGLVCWLLLSREVLPRLGPAVAASKPAYWAAAMVLLTAWMPFNNGLRPEGIIALGSLVTYVLIERSMRYSRLTPAALAVVTAAFTLGVQPTGLIAVAALVAGGRPMLRILVRRHRLVGTLPLVSPMLAAGTVILTVVFADQTLSTVLEATRVRAKIGPSQAWYTENLRYYYLILPTVDGSLSRRFGFLITALCLFTAVFIMLRRKRIPSVARGPAWRLMGVIFGTMFFLMFTPTKWVHHFGLFAAVGAAMAALTTVLVSPSVLRWSRNRMAFLAALFFLLALCWATTNGWWYVSSYGVPFNSAMPKIDGITVSTIFFALFAIAAGYAAWLHFAPRGAGEGRLIRALTTAPVPIVAGFMAAVFVASMVAGIVRQYPTYSNGWSNVRAFVGGCGLADDVLVEPDTNAGFMKPLDGDSGSWGPLGPLGGVNPVGFTPNGVPEHTVAEAIVMKPNQPGTDYDWDAPTKLTSPGINGSTVPLPYGLDPARVPLAGTYTTGAQQQSTLVSAWYLLPKPDDGHPLVVVTAAGKIAGNSVLHGYTPGQTVVLEYAMPGPGALVPAGRMVPDDLYGEQPKAWRNLRFARAKMPADAVAVRVVAEDLSLTPEDWIAVTPPRVPDLRSLQEYVGSTQPVLLDWAVGLAFPCQQPMLHANGIAEIPKFRITPDYSAKKLDTDTWEDGTNGGLLGITDLLLRAHVMATYLSRDWARDWGSLRKFDTLVDAPPAQLELGTATRSGLWSPGKIRIGP