erg3 Resolved · high auto-curated
H37Rv Rv1814 · MTBC0 - ·
300 aa · 2056521–2057423 (+) ·
RefSeq NP_216330.1
Annotation: from legacy to revised
| Legacy (H37Rv / Mycobrowser) | membrane-bound C-5 sterol desaturase |
|---|---|
| MTBC0 PGAP re-annotation | — |
| Revised (this work) | Membrane-bound C-5 sterol desaturase. Pfam: FA_hydroxylase (PF04116.20). |
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 |
P9WNZ9
SwissProt · reviewed
· Inferred from homology
|
|---|---|
| UniProt name | C-5 sterol desaturase |
| EC (curated) |
EC 1.3.-.-
|
Functional vocabulary (eggNOG-mapper, orthology transfer)
| COG category |
I Lipid transport and metabolism
|
|---|---|
| Preferred name | erg3 |
| eggNOG description | sterol desaturase |
| Orthologous group | COG3000 |
| Gene Ontology (17) |
GO:0003674, GO:0003824, GO:0004497, GO:0006629, GO:0006643, GO:0008150, GO:0008152, GO:0009987, GO:0016491, GO:0016705, GO:0016714, GO:0044237 +5 more
|
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 | 0.327 · purifying |
|---|---|
| Polymorphic sites (≥ 0.1% of strains) | 3 synonymous, 3 missense, 0 nonsense, 1 frameshift |
| Disruption | 1 distinct premature-stop/frameshift site(s); most common in 0.26% of strains (377) · 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)
| Pfam | Accession | i-Evalue | Residues | Description |
|---|---|---|---|---|
FA_hydroxylase | PF04116.20 | 5.1e-26 | 94–227 | Fatty acid hydroxylase |
Functional interaction network (STRING v12, guilt-by-association)
Closest characterised functional partner: Rv1816 (HTH-type transcriptional regulator), medium confidence from genomic context alone (score 475 excluding text-mining).
| Partner | Product | Score | No text-mining | Channels (≥400) |
|---|---|---|---|---|
Rv3377c |
type B diterpene cyclase | 879 | 842 | experimental:785 |
Rv3397c phyA |
phytoene synthase | 877 | 840 | experimental:785 |
Rv1815 hyp |
hypothetical protein | 745 | 745 ctx | neighborhood:745 |
Rv1364c |
sigma factor regulatory protein | 722 | 722 | coexpression:717 |
Rv1354c hyp |
hypothetical protein | 666 | 665 | coexpression:654 |
Rv1937 |
oxygenase | 738 | 631 | coexpression:413 |
Rv3254 hyp |
hypothetical protein | 641 | 613 | coexpression:405 |
Rv1751 |
oxidoreductase | 639 | 612 | coexpression:402 |
Rv1260 |
oxidoreductase | 639 | 611 | coexpression:401 |
Rv0575c |
oxidoreductase | 639 | 611 | coexpression:401 |
Rv1371 |
membrane protein | 712 | 576 | coexpression:450 |
Rv3554 fdxB |
electron transfer protein FdxB | 630 | 501 | |
Rv2972c hyp |
hypothetical protein | 497 | 498 | coexpression:498 |
Rv3252c alkB |
transmembrane alkane 1-monooxygenase AlkB | 528 | 484 | |
Rv1816 |
HTH-type transcriptional regulator | 475 | 475 ctx | neighborhood:475 |
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): membrane-bound C-5 sterol desaturase
- Pfam (hmmscan --cut_ga): FA_hydroxylase PF04116.20 (E=5e-26)
- (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_216330.1)
- Domains: Pfam-A via hmmscan --cut_ga — FA_hydroxylase (PF04116.20)
- 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
COG3000 - Curated reference: UniProt P9WNZ9 (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 —
37 functional partner(s); context anchor
Rv1816 - Primary literature: none located yet; annotation rests on the domain/homology sources above.
Ancestral MTBC0 protein sequence
>H37Rv|Rv1814|erg3 MRDPVLFAIPCFLLLLILEWTAARKLESIETAATGQPRPASGAYLTRDSVASISMGLVSIATTAGWKSLALLGYAAIYAYLAPWQLSAHRWYTWVIAIVGVDLLYYSYHRIAHRVRLIWATHQAHHSSEYFNFATALRQKWNNSGEILMWVPLPLMGLPPWMVFCSWSLNLIYQFWVHTERIDRLPRWFEFVFNTPSHHRVHHGMDPVYLDKNYGGILIIWDRLFGSFQPELFRPHYGLTKRVDTFNIWKLQTREYVAIVRDWRSATRLRDRLGYVFGPPGWEPRTIDKSNAAASLVTSR