Rv3707c Resolved · high

H37Rv Rv3707c · MTBC0 - · 336 aa · 4150030–4151040 (-) · RefSeq NP_218224.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotation
Revised (this work)AraH2: endo-D-arabinofuranase, founding member (with AraH1/Rv1754c) of glycoside hydrolase family GH183 (Pfam DUF4185). Cleaves the D-arabinan core of arabinogalactan / lipoarabinomannan, i.e. mycobacterial cell-wall remodelling/degradation. NOTE: RefSeq/PGAP still annotate this gene as a hypothetical protein; it was characterised experimentally by Behrens et al. 2023.

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 I6Y4C4 TrEMBL · unreviewed · Evidence at protein level
UniProt nameDUF4185 domain-containing protein

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category M Cell wall / membrane / envelope biogenesis
eggNOG descriptionDomain of unknown function (DUF4185)
Orthologous groupCOG0739

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 0.344 · purifying
Polymorphic sites (≥ 0.1% of strains) 4 synonymous, 4 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
DUF4185PF13810.13 1.1e-5011–325 Domain of unknown function (DUF4185)

Structural neighbours (Foldseek on the ESMFold model, exploratory)

ESMFold model confidence: mean pLDDT 93.2 (very high). A confident model makes the fold comparison meaningful.

Best matches against the PDB, ranked by Foldseek homology probability. A high probability / TM-score suggests a shared fold; unless flagged sig (E < 0.01) these are fold hypotheses, not assignments.

TargetProbTME-valueDescription
8an0-assembly1_A 1.00 0.90 2.4e-42 sig 8an0-assembly1_A Endo-D-arabinofuranase AraH2 from Mycobacterium tuberculosis
8ic1-assembly1_A 1.00 0.76 1.1e-15 sig 8ic1-assembly1_A endo-alpha-D-arabinanase EndoMA1 D51N mutant from Microbacterium arabinogalactanolyticum in complex with arabinooligosaccharides
8hhv-assembly1_A 1.00 0.74 1.6e-15 sig 8hhv-assembly1_A endo-alpha-D-arabinanase EndoMA1 from Microbacterium arabinogalactanolyticum
6xn0-assembly2_B 1.00 0.53 6.4e-07 sig 6xn0-assembly2_B Crystal structure of GH43_1 enzyme from Xanthomonas citri
1w2t-assembly2_B 1.00 0.52 5.8e-07 sig 1w2t-assembly2_B beta-fructosidase from Thermotoga maritima in complex with raffinose
3qef-assembly1_A 1.00 0.60 6.1e-06 sig 3qef-assembly1_A The structure and function of an arabinan-specific alpha-1,2-arabinofuranosidase identified from screening the activities of bacterial GH43 glycoside hydrolases
6xn1-assembly2_B 1.00 0.52 3.8e-06 sig 6xn1-assembly2_B Crystal structure of the GH43_1 enzyme from Xanthomonas citri complexed with xylose
1uyp-assembly4_D 1.00 0.52 2.8e-06 sig 1uyp-assembly4_D The three-dimensional structure of beta-fructosidase (invertase) from Thermotoga maritima

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

Closest characterised functional partner: pirG (cell surface protein), high confidence from genomic context alone (score 770 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv3810 pirG cell surface protein 770 770 ctx cooccurence:769
Rv0290 eccD3 ESX-3 secretion system protein EccD 762 762 ctx cooccurence:761
Rv3709c ask aspartokinase 757 758 ctx neighborhood:755
Rv3708c asd aspartate-semialdehyde dehydrogenase 757 757 ctx neighborhood:755
Rv3593 lpqF lipoprotein LpqF 753 754 ctx cooccurence:750
Rv2743c hyp hypothetical protein 753 753 ctx cooccurence:752
Rv0817c lmeA hyp hypothetical protein 748 749 ctx cooccurence:747
Rv0518 hyp hypothetical protein 717 718 ctx cooccurence:716
Rv0479c membrane protein 701 702 ctx cooccurence:700
Rv0383c ttfA hyp hypothetical protein 700 700 ctx cooccurence:700
Rv3906c hyp hypothetical protein 690 691 ctx cooccurence:689
Rv1275 lprC lipoprotein LprC 680 680 ctx cooccurence:679
Rv0315 beta-1,3-glucanase 673 673 ctx cooccurence:672
Rv3710 leuA 2-isopropylmalate synthase 672 672 ctx neighborhood:670
Rv1780 hyp hypothetical protein 670 670 ctx cooccurence:670

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

  • MTBC0 PGAP product: hypothetical protein (not yet updated by RefSeq)
  • Pfam: DUF4185 = glycoside hydrolase family GH183
  • Foldseek: endo-D-arabinofuranase AraH2 (PDB 8AN0, E=2e-42, TM=0.90) -- the strongest structural hit in the genome
  • Experimentally characterised as AraH2 by Behrens et al. 2023

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_218224.1)
  • Domains: Pfam-A via hmmscan --cut_ga — DUF4185 (PF13810.13)
  • 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 COG0739
  • Curated reference: UniProt I6Y4C4 (TrEMBL, unreviewed; 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)
  • Model confidence: ESMFold per-residue pLDDT (mean 93.2, very high)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 96 functional partner(s); context anchor pirG
  • Primary literature: Behrens MA, Lahiri S, et al. (2023). Identification of D-arabinan-degrading enzymes in mycobacteria Nature Communications. doi:10.1038/s41467-023-37839-5 PMID:37076525

Ancestral MTBC0 protein sequence

>H37Rv|Rv3707c|
MLRIGPTAGTGTPTGDYGIGATDLCEFVEFPSQLLQVCGDSFAGQGVGFGGWYAPVALHVDTESIDDPAGVRYTGVTGVGTPLLADPTPPGDSQLPAGVVQINRRNYLMVTTTKDLQPQNSRLVRAEAARGGWQTVSGSRRNAAYQDGRQTQISGYYDPVPTPDSPTGWVYIVADSFTRGEPAVLYRATPESFTDRSRWQGWAGGPDGGWNKPPTPLWPDQLGEMSIRQIDGQTVLSYFNASTGNMEVRVAHHPTSLGAAPVTTVVRHDEWPEPAESLPPPYDNRLAQPYGGYISPGSTIDELRIFVSQWDTRARQNGPYRVIQFAVNPFKPWSDP