Rv2239c Family assigned · medium

H37Rv Rv2239c · MTBC0 - · 158 aa · 2511176–2511652 (-) · RefSeq NP_216755.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotation
Revised (this work)S-adenosyl-methionine (SAM)-dependent methyltransferase fold. RefSeq leaves it 'hypothetical protein' (Pfam DUF3052). The AlphaFold model superposes on an O-methyltransferase bound to the product SAH (PDB 8bif; Foldseek prob 1.0, E 2e-5, TM 0.55). STRING context: peroxiredoxin ahpE (Rv2238c). A SAM-MTase fold assignment; the acceptor substrate is not determined.

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 P9WLG9 SwissProt · reviewed · Evidence at protein level
UniProt nameUncharacterized protein Rv2239c

UniProt still lists this protein as Uncharacterized protein Rv2239c; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
eggNOG descriptionProtein of unknown function (DUF3052)
Orthologous group2B57P

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 0.31 · purifying
Polymorphic sites (≥ 0.1% of strains) 1 synonymous, 1 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
DUF3052PF11253.14 1.4e-5529–152 Protein of unknown function (DUF3052)

Structural neighbours (Foldseek on the ESMFold model, exploratory)

ESMFold model confidence: mean pLDDT 81.5 (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
7ux6-assembly1_A 1.00 0.52 1.2e-04 sig 7ux6-assembly1_A Crystal structure of MfnG, an L- and D-tyrosine O-methyltransferase from the marformycin biosynthesis pathway of Streptomyces drozdowiczii, with SAH bound at 1.35 A resolution (P212121 - form I)
7ux6-assembly1_B 1.00 0.53 3.5e-04 sig 7ux6-assembly1_B Crystal structure of MfnG, an L- and D-tyrosine O-methyltransferase from the marformycin biosynthesis pathway of Streptomyces drozdowiczii, with SAH bound at 1.35 A resolution (P212121 - form I)
5gm2-assembly2_K 1.00 0.51 5.4e-04 sig 5gm2-assembly2_K Crystal structure of methyltransferase TleD complexed with SAH and teleocidin A1
5gm2-assembly3_O 1.00 0.47 3.7e-04 sig 5gm2-assembly3_O Crystal structure of methyltransferase TleD complexed with SAH and teleocidin A1
3e8s-assembly1_A-2 1.00 0.48 5.4e-04 sig 3e8s-assembly1_A-2 Crystal structure of Putative SAM Dependent Methyltransferase in Complex with SAH (NP_744700.1) from PSEUDOMONAS PUTIDA KT2440 at 2.10 A resolution
5gm2-assembly2_L 1.00 0.47 7.0e-04 sig 5gm2-assembly2_L Crystal structure of methyltransferase TleD complexed with SAH and teleocidin A1
5gm2-assembly3_N 1.00 0.47 4.5e-04 sig 5gm2-assembly3_N Crystal structure of methyltransferase TleD complexed with SAH and teleocidin A1
3vc2-assembly11_K 1.00 0.48 9.1e-04 sig 3vc2-assembly11_K Crystal structure of geranyl diphosphate C-methyltransferase from Streptomyces coelicolor A3(2) in complex with Mg2+, geranyl diphosphate, and S-adenosyl-L-homocysteine

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

Closest characterised functional partner: ahpE (peroxiredoxin), high confidence from genomic context alone (score 912 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv2238c ahpE peroxiredoxin 972 912 ctx neighborhood:882 textmining:699
Rv2240c hyp hypothetical protein 977 831 ctx neighborhood:829 textmining:870
Rv2699c hyp hypothetical protein 751 752 ctx cooccurence:751
Rv2882c frr ribosome recycling factor 734 734 coexpression:734
Rv1626 pdtaR two-component system transcriptional regulator 732 732 coexpression:732
Rv1630 rpsA 30S ribosomal protein S1 731 731 coexpression:731
Rv2867c GCN5-like N-acetyltransferase 717 718 ctx cooccurence:716
Rv2050 rbpA RNA polymerase-binding protein RbpA 713 714 ctx cooccurence:712
Rv2112c dop pup deamidase/depupylase 663 664 ctx cooccurence:659
Rv2708c hyp hypothetical protein 661 661 ctx cooccurence:658
Rv1460 sufR transcriptional regulator 659 660 ctx cooccurence:659
Rv3676 crp cAMP receptor protein 650 650 ctx cooccurence:645
Rv2572c aspS aspartate--tRNA ligase 634 634 ctx cooccurence:632
Rv2989 transcriptional regulator 614 615 ctx cooccurence:613
Rv3015c hyp hypothetical protein 614 614 ctx cooccurence:614

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

  • Foldseek -> O-methyltransferase + SAH (8bif), prob 1.0, E 2e-5
  • Pfam DUF3052
  • STRING anchor ahpE/Rv2238c
  • Structural homology: AlphaFold DB model + Foldseek vs PDB (project 'Still unknown gene function', phase5-7, 2026-06-10). A fold-level family assignment, not a demonstrated activity.

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_216755.1)
  • Domains: Pfam-A via hmmscan --cut_ga — DUF3052 (PF11253.14)
  • 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 2B57P
  • Curated reference: UniProt P9WLG9 (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)
  • Model confidence: ESMFold per-residue pLDDT (mean 81.5, confident)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 44 functional partner(s); context anchor ahpE
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv2239c|
MPIATVCTWPAETEGGSTVVAADHASNYARKLGIQRDQLIQEWGWDEDTDDDIRAAIEEACGGELLDEDTDEVIDVVLLWWRDGDGDLVDTLMDAIGPLAEDGVIWVVTPKTGQPGHVLPAEIAEAAPTAGLMPTSSVNLGNWSASRLVQPKSRAGKR