citA Resolved · high auto-curated

H37Rv Rv0889c · MTBC0 mtbc0_000944 · 373 aa · 991954–993075 (-) · RefSeq NP_215404.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)citrate synthase 2
MTBC0 PGAP re-annotationcitrate synthase 2
Revised (this work)Citrate synthase 2. Pfam: Citrate_synt (PF00285.27).

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

Curated reference (UniProt)

UniProt P9WPD3 SwissProt · reviewed · Evidence at protein level
UniProt namePutative citrate synthase 2
EC (curated) EC 2.3.3.16

UniProt still lists this protein as Putative citrate synthase 2; the revised annotation above is ahead of the current UniProt record.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category C Energy production and conversion
Preferred namecitA
eggNOG descriptionBelongs to the citrate synthase family
Orthologous groupCOG0372
EC number EC 2.3.3.1
KEGG orthology K01647
KEGG pathways map00020, map00630, map01100, map01110, map01120, map01130, map01200, map01210, map01230
KEGG modules M00009, M00010, M00012, M00740
Gene Ontology (8) GO:0005575, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0044424, GO:0044444, GO:0044464

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 1.789 · diversifying/relaxed
Polymorphic sites (≥ 0.1% of strains) 2 synonymous, 10 missense, 0 nonsense, 2 frameshift
Disruption 2 distinct premature-stop/frameshift site(s); most common in 0.68% of strains (982) · 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
Citrate_syntPF00285.27 6.6e-8711–349 Citrate synthase, C-terminal domain

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

Closest characterised functional partner: gltA2 (citrate synthase 1), high confidence from genomic context alone (score 960 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1475c acn iron-regulated aconitate hydratase 995 991 coexpression:692 database:941 textmining:533
Rv1240 mdh malate dehydrogenase 992 979 coexpression:650 experimental:423 database:900 textmining:672
Rv3667 acs acetyl-CoAsynthetase 971 969 coexpression:649 database:900
Rv0896 gltA2 citrate synthase 1 963 960 ctx neighborhood:493 database:900
Rv2495c bkdC branched-chain keto acid dehydrogenase E2 component 961 955 coexpression:424 database:900
Rv1837c glcB malate synthase 976 949 coexpression:440 database:900 textmining:565
Rv1248c kgd multifunctional 2-oxoglutarate dehydrogenase E1 component /2-oxoglutarate dehydrogenase dihydrolipoyllysine-residue succinyltransferase 985 945 coexpression:912 textmining:744
Rv2852c mqo malate:quinone oxidoreductase 946 941 coexpression:417 database:900
Rv1131 prpC methylcitrate synthase PrpC 938 934 database:900
Rv2967c pca pyruvate carboxylase 961 929 database:900 textmining:486
Rv2455c korA 2-oxoglutarate oxidoreductase subunit KorA 952 907 database:900 textmining:509
Rv2454c korB 2-oxoglutarate oxidoreductase subunit KorB 939 905 database:900
Rv0211 pckA phosphoenolpyruvate carboxykinase 924 902 database:900
Rv1098c fum fumarate hydratase 962 893 coexpression:422 database:800 textmining:668
Rv1731 gabD2 succinate-semialdehyde dehydrogenase 894 890 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: citrate synthase 2
  • MTBC0 PGAP product: citrate synthase 2
  • Pfam (hmmscan --cut_ga): Citrate_synt PF00285.27 (E=7e-87)
  • (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_215404.1)
  • Domains: Pfam-A via hmmscan --cut_ga — Citrate_synt (PF00285.27)
  • 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 COG0372
  • Curated reference: UniProt P9WPD3 (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 — 138 functional partner(s); context anchor gltA2
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_000944|Rv0889c|citA
MTVVPENFVPGLDGVVAFTTEIAEPDKDGGALRYRGVDIEDLVSQRVTFGDVWALLVDGNFGSGLPPAEPFPLPIHSGDVRVDVQAGLAMLAPIWGYAPLLDIDDATARQQLARASVMALSYVAQSARGIYQPAVPQRIIDECSTVTARFMTRWQGEPDPRHIEAIDAYWVSAAEHGMNASTFTARVIASTGADVAAALSGAIGAMSGPLHGGAPARVLPMLDEVERAGDARSVVKGILDRGEKLMGFGHRVYRAEDPRARVLRAAAERLGAPRYEVAVAVEQAALSELRERRPDRAIETNVEFWAAVVLDFARVPANMMPAMFTCGRTAGWCAHILEQKRLGKLVRPSAIYVGPGPRSPESVDGWERVLTTA