Rv3169 Family assigned · medium

H37Rv Rv3169 · MTBC0 mtbc0_003368 · 374 aa · 3562086–3563210 (+) · RefSeq NP_217685.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotationhypothetical protein
Revised (this work)NTF2-like / SnoaL-like superfamily enzyme (polyketide cyclase / steroid-lyase / [4+2]-Diels-Alderase fold). RefSeq leaves it 'hypothetical protein'. Strongest match to 25-phosphosteroid lyase (steroid/cholesterol degradation); a candidate steroid/lipid-processing lyase-cyclase, though the precise substrate within this functionally diverse superfamily is undetermined. RefSeq leaves this locus uncharacterised.

Curated reference (UniProt)

UniProt O53319 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)

Orthologous group2BYTM

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 0.274 · purifying
Polymorphic sites (≥ 0.1% of strains) 6 synonymous, 4 missense, 1 nonsense, 0 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 0.12% of strains (167) · clonal

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)

No Pfam-A domain above the gathering threshold (or not yet scanned).

Structural neighbours (Foldseek on the ESMFold model, exploratory)

ESMFold model confidence: mean pLDDT 94.9 (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
8j1g-assembly1_A 0.30 0.77 2.0e+00 8j1g-assembly1_A Structure of amino acid dehydrogenase in complex with NADPH
3hdj-assembly1_B 0.20 0.75 3.1e+00 3hdj-assembly1_B The crystal structure of probable ornithine cyclodeaminase from Bordetella pertussis Tohama I
8j1c-assembly1_A 0.16 0.75 4.3e+00 8j1c-assembly1_A Structure of amino acid dehydrogenase in complex with NADP
8j1g-assembly2_C 0.15 0.61 2.7e+00 8j1g-assembly2_C Structure of amino acid dehydrogenase in complex with NADPH
4egd-assembly1_A 0.14 0.29 3.3e-01 4egd-assembly1_A 1.85 Angstrom crystal structure of native hypothetical protein SAOUHSC_02783 from Staphylococcus aureus
7red-assembly1_A 0.14 0.21 8.6e-02 7red-assembly1_A Holo Hemophilin from A. baumannii
2wvp-assembly1_A 0.13 0.18 1.7e-02 2wvp-assembly1_A Synthetically modified OmpG
4bih-assembly1_A 0.12 0.54 1.9e+00 4bih-assembly1_A Crystal structure of the conserved staphylococcal antigen 1A, Csa1A

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

Closest characterised functional partner: Rv3168 (aminoglycoside phosphotransferase), high confidence from genomic context alone (score 992 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv3168 aminoglycoside phosphotransferase 997 992 ctx neighborhood:881 cooccurence:765 coexpression:746 textmining:629
Rv3167c TetR family transcriptional regulator 900 804 ctx neighborhood:743 textmining:511
Rv0311 hyp hypothetical protein 718 718 ctx cooccurence:717
Rv0310c hyp hypothetical protein 689 690 ctx cooccurence:688
Rv3170 aofH flavin-containing monoamine oxidase 664 663 ctx neighborhood:617
Rv0138 hyp hypothetical protein 648 648 ctx cooccurence:648
Rv0272c hyp hypothetical protein 643 644 ctx cooccurence:639
Rv1132 hyp hypothetical protein 637 637 ctx cooccurence:636
Rv0767c HTH-type transcriptional regulator 618 618 ctx cooccurence:617
Rv1874 hyp hypothetical protein 567 568 ctx cooccurence:563
Rv3359 oxidoreductase 564 565 ctx cooccurence:561
Rv0762c hyp hypothetical protein 541 541 ctx cooccurence:535
Rv2574 hyp hypothetical protein 523 523 ctx cooccurence:521
Rv0692 mftB mycofactocin system protein MftB 521 522 ctx cooccurence:520
Rv2740 ephG epoxide hydrolase 504 505 ctx cooccurence:499

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

  • HHpred: top hit 9FZN 25-phosphosteroid lyase Prob 100%, E 2.4e-47, 354 cols; followed by kievitone hydratase (CrtC) and multiple Diels-Alderases ([4+2]-cyclases) at 99.8%
  • HHpred web (MPI Bioinformatics Toolkit, profile-profile remote homology), interpreted in project 'Still unknown gene function', 2026-06-10. A fold/family-level assignment, not a demonstrated function.

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_217685.1)
  • Domains: Pfam-A via hmmscan --cut_ga — none above threshold
  • 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 2BYTM
  • Curated reference: UniProt O53319 (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 94.9, very high)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 35 functional partner(s); context anchor Rv3168
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003368|Rv3169|
MPQMLGPLDEYPLHQLPQPIAWPGSSDRNFYDRSYFNAHDRTGNIFLITGIGYYPNLGVKDAFVLIRRADIQTAVHLSDAIDSDRLHQHVNGYRVEVVEPLRKLRIVLDETEGVAADLTWEGLFDVVQEQPHVLRSGNRVTLDAQRFAQLGTWSGRIVVDGERIAVDPATWLGSRDRSWGIRPVGEPEPAGRPADPPFEGMWWLYVPLAFDDFAVVLIIQEEPDGFRSLNDCTRIWRDGHVEQLGWPRVRIHYRSGTRIPTGATIEASTPDGAPVHFDVESKLAVPTHVGGGYGGDSDWSHGMWKGEKFVERRTYDMTDPTIIARAGFGVIDHVGRALCRDGDGNPVQGWGLFEHGALGRHDPSGFADWSTLAP