metC Resolved · high auto-curated

H37Rv Rv3340 · MTBC0 mtbc0_003552 · 449 aa · 3752113–3753462 (+) · RefSeq NP_217857.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)O-acetylhomoserine sulfhydrylase
MTBC0 PGAP re-annotationbifunctional o-acetylhomoserine/o-acetylserine sulfhydrylase
Revised (this work)Bifunctional o-acetylhomoserine/o-acetylserine sulfhydrylase. Pfam: Cys_Met_Meta_PP (PF01053.27).

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

Curated reference (UniProt)

UniProt O53390 TrEMBL · unreviewed · Evidence at protein level
UniProt nameProbable O-acetylhomoserine sulfhydrylase MetC

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category E Amino acid transport and metabolism
Preferred namemetY
eggNOG descriptionO-acetylhomoserine sulfhydrylase
Orthologous groupCOG2873
EC number EC 2.5.1.49
KEGG orthology K01740
KEGG pathways map00270, map01100

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 1.043 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 1 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)

PfamAccessioni-EvalueResiduesDescription
Cys_Met_Meta_PPPF01053.27 8.0e-13319–433 Cys/Met metabolism PLP-dependent enzyme

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

Closest characterised functional partner: metA (homoserine O-acetyltransferase), high confidence from genomic context alone (score 999 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3341 metA homoserine O-acetyltransferase 999 999 ctx neighborhood:872 cooccurence:499 coexpression:817 database:900 textmining:648
Rv2124c metH methionine synthase 984 940 database:900 textmining:755
Rv1079 metB cystathionine gamma-synthase 949 936 database:900
Rv0391 metZ O-succinylhomoserine sulfhydrylase 944 936 database:900
Rv3342 methyltransferase 925 922 ctx neighborhood:872 coexpression:415
Rv1133c metE 5-methyltetrahydropteroyltriglutamate--homocysteine methyltransferase 969 918 database:900 textmining:647
Rv1077 cbs cystathionine beta-synthase 934 914 database:900
Rv0075 aminotransferase 918 906 database:900
Rv2294 cystathionine beta-lyase 918 906 database:900
Rv3248c sahH adenosylhomocysteinase 916 901 database:900
Rv2458 mmuM homocysteine S-methyltransferase MmuM 913 901 database:900
Rv1294 thrA homoserine dehydrogenase 888 872 database:800
Rv1559 ilvA threonine dehydratase IlvA 818 818 database:800
Rv2334 cysK1 O-acetylserine sulfhydrylase 837 812 database:800
Rv3684 lyase 826 812 database:800

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

  • Legacy H37Rv annotation: O-acetylhomoserine sulfhydrylase
  • MTBC0 PGAP product: bifunctional o-acetylhomoserine/o-acetylserine sulfhydrylase
  • Pfam (hmmscan --cut_ga): Cys_Met_Meta_PP PF01053.27 (E=8e-133)
  • (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_217857.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Cys_Met_Meta_PP (PF01053.27)
  • 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 COG2873
  • Curated reference: UniProt O53390 (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)
  • Interaction network: STRING v12.0 (Szklarczyk et al. 2023, doi:10.1093/nar/gkac1000), taxon 83332, CC-BY 4.0 — 42 functional partner(s); context anchor metA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003552|Rv3340|metC
MSADSNSTDADPTAHWSFETKQIHAGQHPDPTTNARALPIYATTSYTFDDTAHAAALFGLEIPGNIYTRIGNPTTDVVEQRIAALEGGVAALFLSSGQAAETFAILNLAGAGDHIVSSPRLYGGTYNLFHYSLAKLGIEVSFVDDPDDLDTWQAAVRPNTKAFFAETISNPQIDLLDTPAVSEVAHRNGVPLIVDNTIATPYLIQPLAQGADIVVHSATKYLGGHGAAIAGVIVDGGNFDWTQGRFPGFTTPDPSYHGVVFAELGPPAFALKARVQLLRDYGSAASPFNAFLVAQGLETLSLRIERHVANAQRVAEFLAARDDVLSVNYAGLPSSPWHERAKRLAPKGTGAVLSFELAGGIEAGKAFVNALKLHSHVANIGDVRSLVIHPASTTHAQLSPAEQLATGVSPGLVRLAVGIEGIDDILADLELGFAAARRFSADPQSVAAF