Rv3399 Resolved · high auto-curated

H37Rv Rv3399 · MTBC0 - · 348 aa · 3816129–3817175 (+) · RefSeq NP_217916.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)S-adenosylmethionine-dependent methyltransferase
MTBC0 PGAP re-annotation
Revised (this work)S-adenosylmethionine-dependent methyltransferase. Pfam: LCM (PF04072.21).

Auto-curated: this verdict and function were generated by rules from PGAP + Pfam + Foldseek and have not been hand-reviewed.

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 P9WFH1 SwissProt · reviewed · Evidence at protein level
UniProt namePutative S-adenosyl-L-methionine-dependent methyltransferase Rv3399
EC (curated) EC 2.1.1.-
Curated functionExhibits S-adenosyl-L-methionine-dependent methyltransferase activity.

UniProt still lists this protein as Putative S-adenosyl-L-methionine-dependent methyltransferase Rv3399; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category H Coenzyme transport and metabolism
eggNOG descriptionExhibits S-adenosyl-L-methionine-dependent methyltransferase activity
Orthologous groupCOG3315

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 0.65 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 4 synonymous, 8 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
LCMPF04072.21 2.9e-7061–244 Leucine carboxyl methyltransferase

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

Closest characterised functional partner: phyA (phytoene synthase), high confidence from genomic context alone (score 880 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3397c phyA phytoene synthase 880 880 ctx neighborhood:508 coexpression:767
Rv3398c idsA1 multifunctional dimethylallyltransferase/geranyltranstransferase/farnesyltranstransferase 789 789 ctx neighborhood:567 coexpression:458
Rv3400 hydrolase 638 638 ctx neighborhood:633
Rv3401 glycosyl hydrolase 620 621 ctx neighborhood:609
Rv3396c guaA GMP synthase 507 507 ctx neighborhood:502
Rv0401 transmembrane protein 461 462 ctx neighborhood:462
Rv0400c fadE7 acyl-CoA dehydrogenase FadE7 426 426 ctx neighborhood:423
Rv2794c pptT 4'-phosphopantetheinyl transferase 400 401
Rv0155 pntAa NAD(P) transhydrogenase subunit alpha PntAa 415 49 textmining:411

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

  • Annotation from H37Rv (no MTBC0 1:1 anchor; H37Rv protein used): S-adenosylmethionine-dependent methyltransferase
  • Pfam (hmmscan --cut_ga): LCM PF04072.21 (E=3e-70)
  • (auto-curated by rules from PGAP + Pfam + Foldseek; not hand-reviewed)

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_217916.1)
  • Domains: Pfam-A via hmmscan --cut_ga — LCM (PF04072.21)
  • 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 COG3315
  • Curated reference: UniProt P9WFH1 (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)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 9 functional partner(s); context anchor phyA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv3399|
MARPMGKLPSNTRKCAQCAMAEALLEIAGQTINQKDLGRSGRMTRTDNDTWDLASSVGATATMIATARALASRAENPLINDPFAEPLVRAVGIDLFTRLASGELRLEDIGDHATGGRWMIDNIAIRTKFYDDFFGDATTAGIRQVVILAAGLDTRAYRLPWPPGTVVYEIDQPAVIKFKTRALANLNAEPNAERHAVAVDLRNDWPTALKNAGFDPARPTAFSAEGLLSYLPPQGQDRLLDAITALSAPDSRLATQSPLVLDLAEEDEKKMRMKSAAEAWRERGFDLDLTELIYFDQRNDVADYLAGSGWQVTTSTGKELFAAQGLPPFADDHITRFADRRYISAVLK