Rv1754c Resolved · high

H37Rv Rv1754c · MTBC0 mtbc0_001867 · 563 aa · 1997815–1999506 (-) · RefSeq NP_216270.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationDUF4185 domain-containing protein
Revised (this work)AraH1: endo-D-arabinanase of glycoside hydrolase family GH183 (Pfam DUF4185). With AraH2 (Rv3707c), cleaves the D-arabinan of arabinogalactan/lipoarabinomannan, with a distinct substrate preference; involved in mycobacterial cell-wall modification/degradation.

Curated reference (UniProt)

UniProt O06790 TrEMBL · unreviewed · Evidence at protein level
UniProt nameConserved protein

UniProt still lists this protein as Conserved protein; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category G Carbohydrate transport and metabolism
eggNOG descriptionDomain of unknown function (DUF4185)
Orthologous groupCOG4409

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 1.156 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 7 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 4.1e-119234–559 Domain of unknown function (DUF4185)

Structural neighbours (Foldseek on the ESMFold model, exploratory)

ESMFold model confidence: mean pLDDT 83.6 (confident). 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
8ic1-assembly1_A 1.00 0.84 3.9e-36 sig 8ic1-assembly1_A endo-alpha-D-arabinanase EndoMA1 D51N mutant from Microbacterium arabinogalactanolyticum in complex with arabinooligosaccharides
8hhv-assembly1_A 1.00 0.84 4.9e-36 sig 8hhv-assembly1_A endo-alpha-D-arabinanase EndoMA1 from Microbacterium arabinogalactanolyticum
8glv-assembly1_Gs 0.01 0.09 4.7e+00 8glv-assembly1_Gs 96-nm repeat unit of doublet microtubules from Chlamydomonas reinhardtii flagella
6u42-assembly1_5F 0.01 0.08 4.2e+00 6u42-assembly1_5F Natively decorated ciliary doublet microtubule

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

Closest characterised functional partner: Rv3668c (protease), high confidence from genomic context alone (score 754 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv3668c protease 769 754 ctx cooccurence:601
Rv0888 spmT hyp hypothetical protein 764 733 coexpression:732
Rv0312 hyp hypothetical protein 714 696 coexpression:625
Rv0431 tuberculin-like peptide 679 679 ctx cooccurence:676
Rv0053 rpsF 30S ribosomal protein S6 631 632 experimental:405
Rv3707c hyp hypothetical protein 579 579 ctx cooccurence:573
Rv1288 hyp hypothetical protein 568 541
Rv3499c mce4A Mce family protein Mce4A 537 537 ctx cooccurence:455
Rv0979A rpmF 50S ribosomal protein L32 534 534 experimental:405
Rv3443c rplM 50S ribosomal protein L13 533 534 experimental:405
Rv0682 rpsL 30S ribosomal protein S12 556 532 experimental:405
Rv2890c rpsB 30S ribosomal protein S2 550 528 experimental:405
Rv0720 rplR 50S ribosomal protein L18 527 528 experimental:405
Rv0714 rplN 50S ribosomal protein L14 526 526 experimental:405
Rv1642 rpmI 50S ribosomal protein L35 529 511 experimental:405

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: DUF4185 domain-containing protein
  • Pfam: DUF4185 = glycoside hydrolase family GH183
  • Foldseek: endo-alpha-D-arabinanase EndoMA1 (PDB 8IC1, E=4e-36, TM=0.84)
  • Experimentally characterised as AraH1 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_216270.1)
  • 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 COG4409
  • Curated reference: UniProt O06790 (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 83.6, confident)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 114 functional partner(s); context anchor Rv3668c
  • 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

>mtbc0_001867|Rv1754c|
MYRYQVRVQQRRSEMNRWVATRSRRHTYQWITDHKSPRDHYRHISELRTSIATSSPGRCDMSPIPRIVSVSLAWAAAIGLMVPIGLAPPAMAAPCSGDAANAPPPPSAIVTDPGATALGPVRPGHGPIPTGRKPRGANDRAPLPKLGPLISALLNPGARNAAPLQQQALVPRANPGPNPAPNPPATGPQPPNATQLTPNPAPAPDPAPAAAPDPGATLAGATTSLAEWVTGPDSPNKTLERFGISGTDLGIPWDNGDPANRQVLMIFGDTFGYCAVDGHQWRYNTLFRSQDRDLGNGVHVTSGDASNRYSGSPVRQPGFSKQLINSIKWARDETGIIPTAGIAVGKTQYVNFMSIRNWGRDGEWTTNYSGIAVSKDNGQTWGVFPGTIRASGPDSGGKARFVPGNENFQMGAYLKSNDGYLYSFGTPPGRGGSAYLARVPQRFVPDLTKYQYWNGDSNSWVPNKPDAATPVIPGPVGEMSVQYNTYLKQYLALYTNGMNDVVARTAPAPQGPWSAEQMLVSSWQMPGGIYAPMMHPWSTGKDVYFNLSLWSAYNVMLMHTVLP