ilvX Family assigned · medium auto-curated

H37Rv Rv3509c · MTBC0 mtbc0_003724 · 515 aa · 3962055–3963602 (-) · RefSeq NP_218026.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)acetohydroxyacid synthase large subunit
MTBC0 PGAP re-annotationacetolactate synthase large subunit
Revised (this work)Acetolactate synthase large subunit. Pfam: TPP_enzyme_N (PF02776.24), TPP_enzyme_C (PF02775.27).

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

Curated reference (UniProt)

UniProt O53554 SwissProt · reviewed · Evidence at protein level
UniProt namePutative acetolactate synthase large subunit IlvX
EC (curated) EC 2.2.1.6
Curated functionCatalyzes the conversion of 2 pyruvate molecules into acetolactate in the first common step of the biosynthetic pathway of the branched-amino acids such as leucine, isoleucine, and valine.

UniProt still lists this protein as Putative acetolactate synthase large subunit IlvX; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category E Amino acid transport and metabolism
H Coenzyme transport and metabolism
Preferred nameilvX
eggNOG descriptionThiamine pyrophosphate enzyme, C-terminal TPP binding domain
Orthologous groupCOG0028
EC number EC 2.2.1.6
KEGG orthology K01652
KEGG pathways map00290, map00650, map00660, map00770, map01100, map01110, map01130, map01210, map01230
KEGG modules M00019, M00570
Gene Ontology (38) GO:0005575, GO:0005576, GO:0005618, GO:0005623, GO:0005886, GO:0006082, GO:0006520, GO:0006549, GO:0006573, GO:0006807, GO:0008150, GO:0008152 +26 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 0.381 · purifying
Polymorphic sites (≥ 0.1% of strains) 6 synonymous, 6 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
TPP_enzyme_NPF02776.24 5.8e-301–108 Thiamine pyrophosphate enzyme, N-terminal TPP binding domain
TPP_enzyme_CPF02775.27 6.0e-30374–508 Thiamine pyrophosphate enzyme, C-terminal TPP binding domain

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

PartnerProductScoreNo text-miningChannels (≥400)
Rv3002c ilvN acetolactate synthase small subunit 995 992 coexpression:648 experimental:704 database:900 textmining:490
Rv3001c ilvC ketol-acid reductoisomerase 980 964 coexpression:540 database:900 textmining:479
Rv2995c leuB 3-isopropylmalate dehydrogenase 960 948 coexpression:409 database:900
Rv1559 ilvA threonine dehydratase IlvA 957 935 database:900
Rv3470c ilvB2 acetolactate synthase large subunit 990 926 database:900 textmining:870
Rv3710 leuA 2-isopropylmalate synthase 950 919 database:872 textmining:414
Rv2455c korA 2-oxoglutarate oxidoreductase subunit KorA 935 915 database:900
Rv3003c ilvB1 acetolactate synthase large subunit IlvB 943 911 database:900
Rv2454c korB 2-oxoglutarate oxidoreductase subunit KorB 911 906 database:900
Rv1820 ilvG acetolactate synthase large subunit IlvG 937 901 database:900
Rv0694 mftD mycofactocin system heme/flavin oxidoreductase MftD 904 899 database:893
Rv1872c lldD2 L-lactate dehydrogenase 904 899 database:893
Rv3510c hyp hypothetical protein 882 882 ctx neighborhood:881
Rv2332 mez malate oxidoreductase 854 844 database:800
Rv1617 pykA pyruvate kinase 851 836 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: acetohydroxyacid synthase large subunit
  • MTBC0 PGAP product: acetolactate synthase large subunit
  • Pfam (hmmscan --cut_ga): TPP_enzyme_N PF02776.24 (E=6e-30), TPP_enzyme_C PF02775.27 (E=6e-30)
  • (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_218026.1)
  • Domains: Pfam-A via hmmscan --cut_ga — TPP_enzyme_N (PF02776.24), TPP_enzyme_C (PF02775.27)
  • 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 COG0028
  • Curated reference: UniProt O53554 (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 — 162 functional partner(s)
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_003724|Rv3509c|ilvX
MNGAQALINTLVDGGVDVCFANPGTSEMHFVAALDAVPRMRGMLTLFEGVATGAADGYARIAGRPAAVLLHLGPGLGNGLANLHNARRARVPMVVVVGDHATYHKKYDAPLESDIDAVAGTVSGWVRRTEAAADVGADAEAAIAASRSGSQIATLILPADVCWSDGAHAAAGVPAQAAAAPVDVGPVAGVLRSGEPAMMLIGGDATRGPGLTAAARIVQATGARWLCETFPTCLERGAGIPAVERLAYFAEGAAAQLDGVKHLVLAGARSPVSFFAYPGMPSDLVPAGCEVHVLAEPGGAADALAALADEVAPGTVAPVAGASRPQLPTGDLTSVSAADVVGALLPERAIVVDESNTCGVLLPQATAGAPAHDWLTLTGGAIGYGIPAAVGAAVAAPDRPVLCLESDGSAMYTISGLWSQARENLDVTTVIYNNGAYDILRIELQRVGAGSDPGPKALDLLDISRPTMDFVKIAEGMGVPARRVTTCEEFADALRAAFAEPGPHLIDVVVPSLVG