echA18 Resolved · high auto-curated

H37Rv Rv3373 · MTBC0 - · 213 aa · 3787726–3788367 (+) · RefSeq NP_217890.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)enoyl-CoA hydratase
MTBC0 PGAP re-annotation
Revised (this work)Enoyl-CoA hydratase. Pfam: ECH_1 (PF00378.26), ECH_2 (PF16113.11).

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 O50402 TrEMBL · unreviewed · Evidence at protein level
UniProt nameProbable enoyl-CoA hydratase EchA18
Curated functionCould possibly oxidize fatty acids using specific components.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category I Lipid transport and metabolism
Preferred nameechA18
eggNOG descriptionEnoyl-CoA hydratase/isomerase
Orthologous groupCOG1024
EC number EC 4.2.1.17
KEGG orthology K01692
KEGG pathways map00071, map00280, map00281, map00310, map00360, map00362, map00380, map00410, map00627, map00640, map00650, map00903, map00930, map01100, map01110, map01120, map01130, map01212
KEGG modules M00032, M00087

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 1.198 · relaxed/neutral
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 7 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
ECH_1PF00378.26 1.0e-4046–213 Enoyl-CoA hydratase/isomerase
ECH_2PF16113.11 4.1e-2450–208 Enoyl-CoA hydratase/isomerase

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

Closest characterised functional partner: echA18.1 (Probable enoyl-CoA hydratase EchA18.1 (Enoyl hydrase) (Unsaturated acyl-CoA hydratase) (Crotonase); Rv3374, (MTV004.32), len: 82 aa. Probabl), high confidence from genomic context alone (score 877 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv3374 echA18.1 Probable enoyl-CoA hydratase EchA18.1 (Enoyl hydrase) (Unsaturated acyl-CoA hydratase) (Crotonase); Rv3374, (MTV004.32), len: 82 aa. Probabl 898 877 ctx neighborhood:773 fusion:458
Rv0468 fadB2 3-hydroxybutyryl-CoA dehydrogenase 878 871 ctx cooccurence:461 database:650
Rv1715 fadB3 3-hydroxybutyryl-CoA dehydrogenase FadB 872 864 ctx cooccurence:458 database:650
Rv0231 fadE4 acyl-CoA dehydrogenase FadE4 851 846 database:750
Rv0131c fadE1 acyl-CoA dehydrogenase FadE1 851 846 database:750
Rv0154c fadE2 acyl-CoA dehydrogenase FadE2 850 845 database:750
Rv2500c fadE19 acyl-CoA dehydrogenase FadE19 849 844 database:750
Rv0975c fadE13 acyl-CoA dehydrogenase FadE13 849 844 database:750
Rv0400c fadE7 acyl-CoA dehydrogenase FadE7 849 844 database:750
Rv3140 fadE23 acyl-CoA dehydrogenase FadE23 849 844 database:750
Rv3375 amiD amidase 902 805 ctx neighborhood:799 textmining:519
Rv2524c fas fatty acid synthase 815 788 coexpression:644
Rv3563 fadE32 acyl-CoA dehydrogenase FadE32 786 778 database:643
Rv1141c echA11 enoyl-CoA hydratase EchA11 773 773 ctx cooccurence:773
Rv1136 Possible enoyl-CoA hydratase; Rv1136, (MTCI65.03), len: 113 aa. Probable enoyl-CoA hydratase (possible gene fragment). Some similarity to N- 780 772 ctx cooccurence:766

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): enoyl-CoA hydratase
  • Pfam (hmmscan --cut_ga): ECH_1 PF00378.26 (E=1e-40), ECH_2 PF16113.11 (E=4e-24)
  • (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_217890.1)
  • Domains: Pfam-A via hmmscan --cut_ga — ECH_1 (PF00378.26), ECH_2 (PF16113.11)
  • 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 COG1024
  • Curated reference: UniProt O50402 (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 — 156 functional partner(s); context anchor echA18.1
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv3373|echA18
MRRRAMTKMDEASNPCGGDIEAEMCQLMREQPPAEGVVDRVALQRHRNVALITLSHPQAQNALNLASWRRLKRLLDDLAGESGLRAVVLRGAGDKAFAAGADIKEFPNTRMSAADAAEYNESLAVCLRALTTMPIPVIAAVRGLAVGGGCELATACDVCIATDDARFGIPLGKLGVTTGFTEADTVARLIGPAALKYLLFSGELIGIEEAARW