pyrB Family assigned · medium auto-curated

H37Rv Rv1380 · MTBC0 mtbc0_001481 · 319 aa · 1562576–1563535 (+) · RefSeq NP_215896.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)aspartate carbamoyltransferase
MTBC0 PGAP re-annotationaspartate carbamoyltransferase catalytic subunit
Revised (this work)Aspartate carbamoyltransferase catalytic subunit. Pfam: OTCace_N (PF02729.27), OTCace (PF00185.31).

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

Curated reference (UniProt)

UniProt P9WIT7 SwissProt · reviewed · Evidence at protein level
UniProt nameAspartate carbamoyltransferase catalytic subunit
EC (curated) EC 2.1.3.2
Curated functionCatalyzes the condensation of carbamoyl phosphate and aspartate to form carbamoyl aspartate and inorganic phosphate, the committed step in the de novo pyrimidine nucleotide biosynthesis pathway.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category F Nucleotide transport and metabolism
Preferred namepyrB
eggNOG descriptionBelongs to the ATCase OTCase family
Orthologous groupCOG0540
EC number EC 2.1.3.2
KEGG orthology K00609
KEGG pathways map00240, map00250, map01100
KEGG modules M00051
Gene Ontology (64) GO:0003674, GO:0003824, GO:0004070, GO:0005575, GO:0005618, GO:0005622, GO:0005623, GO:0005737, GO:0005829, GO:0005886, GO:0006139, GO:0006220 +52 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 0.297 · purifying
Polymorphic sites (≥ 0.1% of strains) 5 synonymous, 4 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
OTCace_NPF02729.27 1.0e-414–153 Aspartate/ornithine carbamoyltransferase, carbamoyl-P binding domain
OTCacePF00185.31 1.1e-19160–305 Aspartate/ornithine carbamoyltransferase, Asp/Orn binding domain

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

Closest characterised functional partner: carA (carbamoyl-phosphate synthase small subunit), high confidence from genomic context alone (score 1000 excluding text-mining).

PartnerProductScoreNo text-miningChannels (≥400)
Rv1383 carA carbamoyl-phosphate synthase small subunit 999 1000 ctx neighborhood:882 fusion:900 cooccurence:422 coexpression:865 database:900 textmining:449
Rv1381 pyrC dihydroorotase 999 1000 ctx neighborhood:882 fusion:900 cooccurence:771 coexpression:958 experimental:915 database:900 textmining:815
Rv1384 carB carbamoyl-phosphate synthase large subunit 999 1000 ctx neighborhood:882 fusion:900 cooccurence:508 coexpression:861 database:900 textmining:860
Rv1379 pyrR bifunctional pyrimidine operon regulatory protein/uracil phosphoribosyltransferase 998 997 ctx neighborhood:882 cooccurence:727 coexpression:860 experimental:444 textmining:436
Rv1385 pyrF orotidine 5'-phosphate decarboxylase 992 983 ctx neighborhood:881 coexpression:859 textmining:588
Rv1382 hyp hypothetical protein 981 975 ctx neighborhood:882 coexpression:794
Rv1416 ribH 6,7-dimethyl-8-ribityllumazine synthase 948 948 coexpression:945
Rv0357c purA adenylosuccinate synthetase 943 926 database:900
Rv2139 pyrD dihydroorotate dehydrogenase 960 913 coexpression:857 textmining:571
Rv2201 asnB asparagine synthetase 922 910 database:900
Rv1658 argG argininosuccinate synthase 912 907 database:900
Rv1595 nadB L-aspartate oxidase 909 902 database:900
Rv1538c ansA L-aparaginase 906 902 database:900
Rv1656 argF ornithine carbamoyltransferase 861 840 database:800
Rv3709c ask aspartokinase 821 804 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: aspartate carbamoyltransferase
  • MTBC0 PGAP product: aspartate carbamoyltransferase catalytic subunit
  • Pfam (hmmscan --cut_ga): OTCace_N PF02729.27 (E=1e-41), OTCace PF00185.31 (E=1e-19)
  • (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_215896.1)
  • Domains: Pfam-A via hmmscan --cut_ga — OTCace_N (PF02729.27), OTCace (PF00185.31)
  • 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 COG0540
  • Curated reference: UniProt P9WIT7 (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 — 87 functional partner(s); context anchor carA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>mtbc0_001481|Rv1380|pyrB
MTPRHLLTAADLSRDDATAILDDADRFAQALVGRDIKKLPTLRGRTVVTMFYENSTRTRVSFEVAGKWMSADVINVSAAGSSVGKGESLRDTALTLRAAGADALIIRHPASGAAHLLAQWTGAHNDGPAVINAGDGTHEHPTQALLDALTIRQRLGGIEGRRIVIVGDILHSRVARSNVMLLDTLGAEVVLVAPPTLLPVGVTGWPATVSHDFDAELPAADAVLMLRVQAERMNGGFFPSVREYSVRYGLTERRQAMLPGHAVVLHPGPMVRGMEITSSVADSSQSAVLQQVSNGVQVRMAVLFHVLVGAQDAGKEGAA