Rv3205c Family assigned · low

H37Rv Rv3205c · MTBC0 - · 292 aa · 3581627–3582505 (-) · RefSeq NP_217721.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)hypothetical protein
MTBC0 PGAP re-annotation
Revised (this work)Protein-kinase-like (APH/ePK) fold whose active site is NOT retained. RefSeq leaves it 'hypothetical protein'. The AlphaFold model superposes on an aminoglycoside 3',5"-phosphotransferase (PDB 1l8t = M-CSA entry 640, EC 2.7.1.95), but the M-CSA active-site check shows the 4 catalytic residues are all ALIGNED yet SUBSTITUTED (0/4 conserved) -> same fold, active site not retained. A worked negative control: the kinase fold is present but the gene is NOT an active aminoglycoside phosphotransferase.

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 O05861 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 S Function unknown
eggNOG descriptionAminoglycoside phosphotransferase
Orthologous groupCOG2334

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 0.557 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 3 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)

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 91.9 (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
2ppq-assembly1_A-2 1.00 0.58 5.2e-08 sig 2ppq-assembly1_A-2 Crystal structure of the homoserine kinase from Agrobacterium tumefaciens
3i0q-assembly1_A 1.00 0.55 2.0e-05 sig 3i0q-assembly1_A Crystal Structure of the AMP-bound complex of Spectinomycin Phosphotransferase, APH(9)-Ia
1l8t-assembly1_A 1.00 0.48 1.1e-05 sig 1l8t-assembly1_A Crystal Structure Of 3',5"-Aminoglycoside Phosphotransferase Type IIIa ADP Kanamycin A Complex
3i0o-assembly1_A 1.00 0.53 4.9e-05 sig 3i0o-assembly1_A Crystal Structure of Spectinomycin Phosphotransferase, APH(9)-Ia, in complex with ADP and Spectinomcyin
2q83-assembly2_B 1.00 0.48 4.2e-05 sig 2q83-assembly2_B Crystal structure of ytaA (2635576) from Bacillus subtilis at 2.50 A resolution
8i8h-assembly1_A 1.00 0.53 3.8e-04 sig 8i8h-assembly1_A Crystal structure of Cph001-D189N in complex with VIO and ATP
4fex-assembly3_C 1.00 0.51 5.6e-04 sig 4fex-assembly3_C Crystal structure of the aminoglycoside phosphotransferase APH(3')-Ia, with substrate kanamycin and small molecule inhibitor tyrphostin AG1478
4few-assembly9_F 1.00 0.49 6.3e-04 sig 4few-assembly9_F Crystal structure of the aminoglycoside phosphotransferase APH(3')-Ia, with substrate kanamycin and small molecule inhibitor pyrazolopyrimidine PP2

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

Closest characterised functional partner: moeB1 (adenylyltransferase/sulfurtransferase MoeZ), high confidence from genomic context alone (score 784 excluding text-mining). This association is the citable seed of a function hypothesis for this hypothetical protein.

PartnerProductScoreNo text-miningChannels (≥400)
Rv3212 hyp hypothetical protein 811 811 ctx cooccurence:759
Rv3206c moeB1 adenylyltransferase/sulfurtransferase MoeZ 785 784 ctx neighborhood:739
Rv0358 hyp hypothetical protein 781 781 ctx cooccurence:773
Rv2732c transmembrane protein 780 781 ctx cooccurence:774
Rv3438 hyp hypothetical protein 777 778 ctx cooccurence:772
Rv2446c integral membrane protein 776 776 ctx cooccurence:773
Rv0556 transmembrane protein 773 774 ctx cooccurence:773
Rv3850 hyp hypothetical protein 773 773 ctx cooccurence:772
Rv1109c hyp hypothetical protein 771 771 ctx cooccurence:770
Rv0863 hyp hypothetical protein 770 770 ctx cooccurence:769
Rv0475 hbhA heparin binding hemagglutinin HbhA 760 760 ctx cooccurence:758
Rv1083 hyp hypothetical protein 760 760 ctx cooccurence:760
Rv3311 hyp hypothetical protein 757 758 ctx cooccurence:756
Rv2171 lppM lipoprotein LppM 754 755 ctx cooccurence:745
Rv3217c integral membrane protein 753 754 ctx cooccurence:746

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 -> aminoglycoside phosphotransferase (1l8t), prob 1.0, E 2e-5
  • M-CSA 640 active-site check: 4/4 catalytic residues aligned, 0/4 identical -> FOLD-ONLY
  • Fold present, activity not retained (do not requalify as enzyme)
  • 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_217721.1)
  • 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 COG2334
  • Curated reference: UniProt O05861 (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 91.9, very high)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 123 functional partner(s); context anchor moeB1
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv3205c|
MGSTRLTGVNVEPPPEHVLVAFGLAGAQPILLGAGWEGGWRCGEVVLSMVADNARAAWSARVRETLFVDGVRLARPVRSTDGRYVVSGWRADTFVAGAPEPRHDEVVSAAVRLHEATGKLERPRFLTQGPAAPWAEIDVFVAADRAGWEERPLQSVPPGVPTAPPAADPQRSIDLINQLAGLRKPTKSPNQLVHGDLYGTVLFAGTAPPGITDITPYWRPASWAAGVAVVDALSWGAADDGLIERWNALPEWPQMLLRALMFRLAVYALHPRSTAEAFPGLAHTAALVRLVL