speE Resolved · high auto-curated

H37Rv Rv2601 · MTBC0 - · 523 aa · 2928388–2929959 (+) · RefSeq YP_177892.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)spermidine synthase
MTBC0 PGAP re-annotation
Revised (this work)Spermidine synthase. Pfam: Spermine_synth (PF01564.24).

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 P9WGE5 SwissProt · reviewed · Inferred from homology
UniProt namePolyamine aminopropyltransferase
EC (curated) EC 2.5.1.16
Curated functionCatalyzes the irreversible transfer of a propylamine group from the amino donor S-adenosylmethioninamine (decarboxy-AdoMet) to putrescine (1,4-diaminobutane) to yield spermidine.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category S Function unknown
Preferred namespeE
eggNOG descriptionCatalyzes the irreversible transfer of a propylamine group from the amino donor S-adenosylmethioninamine (decarboxy- AdoMet) to putrescine (1,4-diaminobutane) to yield spermidine
Orthologous groupCOG4262
EC number EC 2.5.1.16
KEGG orthology K00797
KEGG pathways map00270, map00330, map00410, map00480, map01100
KEGG modules M00034, M00133
Gene Ontology (6) GO:0005575, GO:0005618, GO:0005623, GO:0030312, GO:0044464, GO:0071944

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 0.701 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 5 synonymous, 9 missense, 0 nonsense, 1 frameshift
Disruption 1 distinct premature-stop/frameshift site(s); most common in 0.13% of strains (192) · 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)

PfamAccessioni-EvalueResiduesDescription
Spermine_synthPF01564.24 2.5e-33298–460 Spermine/spermidine synthase domain

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

Closest characterised functional partner: Rv2600 (integral membrane protein), high confidence from genomic context alone (score 953 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv2600 integral membrane protein 952 953 ctx neighborhood:881 cooccurence:596
Rv2598 hyp hypothetical protein 912 912 ctx neighborhood:638 cooccurence:757
Rv2597 membrane protein 905 906 ctx neighborhood:629 cooccurence:753
Rv0535 pnp 5'-methylthioadenosine phosphorylase 986 901 database:900 textmining:870
Rv0091 mtn 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase 979 900 database:900 textmining:804
Rv2599 membrane protein 650 650 ctx neighborhood:638
Rv2602 vapC41 ribonuclease VapC41 531 531 ctx neighborhood:528
Rv2601A vapB41 antitoxin VapB41 530 529 ctx neighborhood:528
Rv2596 vapC40 ribonuclease VapC40 416 416 ctx neighborhood:410
Rv3033 hyp hypothetical protein 412 413 ctx cooccurence:407
Rv2595 vapB40 antitoxin VapB40 410 410 ctx neighborhood:410
Rv0671 lpqP lipoprotein LpqP 608 190 textmining:537
Rv1905c aao D-amino acid oxidase 412 171
Rv0075 aminotransferase 685 102 textmining:664
Rv2294 cystathionine beta-lyase 670 96 textmining:651

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): spermidine synthase
  • Pfam (hmmscan --cut_ga): Spermine_synth PF01564.24 (E=3e-33)
  • (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 YP_177892.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Spermine_synth (PF01564.24)
  • 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 COG4262
  • Curated reference: UniProt P9WGE5 (SwissProt, reviewed; Inferred from homology)
  • 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 — 24 functional partner(s); context anchor Rv2600
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv2601|speE
MTSTRQAGEATEASVRWRAVLLAAVAACAACGLVYELALLTLAASLNGGGIVATSLIVAGYIAALGAGALLIKPLLAHAAIAFIAVEAVLGIIGGLSAAALYAAFAFLDELDGSTLVLAVGTALIGGLVGAEVPLLMTLLQRGRVAGAADAGRTLANLNAADYLGALVGGLAWPFLLLPQLGMIRGAAVTGIVNLAAAGVVSIFLLRHVVSGRQLVTALCALAAALGLIATLLVHSHDIETTGRQQLYADPIIAYRHSAYQEIVVTRRGDDLRLYLDGGLQFCTRDEYRYTESLVYPAVSDGARSVLVLGGGDGLAARELLRQPGIEQIVQVELDPAVIELARTTLRDVNAGSLDNPRVHVVIDDAMSWLRGAAVPPAGFDAVIVDLRDPDTPVLGRLYSTEFYALAARALAPGGLMVVQAGSPYSTPTAFWRIISTIRSAGYAVTPYHVHVPTFGDWGFALARLTDIAPTPAVPSTAPALRFLDQQVLEAATVFSGDIRPRTLDPSTLDNPHIVEDMRHGWD