carB Family assigned · medium auto-curated

H37Rv Rv1384 · MTBC0 - · 1115 aa · 1557101–1560448 (+) · RefSeq YP_177804.1

Annotation: from legacy to revised

Legacy (H37Rv / Mycobrowser)carbamoyl-phosphate synthase large subunit
MTBC0 PGAP re-annotation
Revised (this work)Carbamoyl-phosphate synthase large subunit. Pfam: CPSase_L_D2 (PF02786.23), CPSase_L_D3 (PF02787.26), CPSase_L_D1 (PF25596.2), Dala_Dala_lig_C (PF07478.19), ATP-grasp (PF02222.28), MGS (PF02142.28).

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 P9WPK3 SwissProt · reviewed · Evidence at protein level
UniProt nameCarbamoyl phosphate synthase large chain
EC (curated) EC 6.3.4.16, EC 6.3.5.5
Curated functionLarge subunit of the glutamine-dependent carbamoyl phosphate synthetase (CPSase). CPSase catalyzes the formation of carbamoyl phosphate from the ammonia moiety of glutamine, carbonate, and phosphate donated by ATP, constituting the first step of 2 biosynthetic pathways, one leading to arginine and/or urea and the other to pyrimidine nucleotides. The large subunit (synthetase) binds the substrates ammonia (free or transferred from glutamine from the small subunit), hydrogencarbonate and ATP and carries out an ATP-coupled ligase reaction, activating hydrogencarbonate by forming carboxy phosphate.

Functional vocabulary (eggNOG-mapper, orthology transfer)

COG category F Nucleotide transport and metabolism
Preferred namecarB
eggNOG descriptionCarbamoyl-phosphate synthetase ammonia chain
Orthologous groupCOG0458
EC number EC 6.3.5.5
KEGG orthology K01955
KEGG pathways map00240, map00250, map01100
KEGG modules M00051
Gene Ontology (50) GO:0000050, GO:0003674, GO:0003824, GO:0004087, GO:0004088, GO:0005575, GO:0005622, GO:0005623, GO:0005737, GO:0005886, GO:0006082, GO:0006520 +38 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 0.4 · purifying
Polymorphic sites (≥ 0.1% of strains) 13 synonymous, 15 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
CPSase_L_D2PF02786.23 2.4e-65133–339 Carbamoyl-phosphate synthase L chain, ATP binding domain
CPSase_L_D3PF02787.26 3.3e-21429–505 Carbamoyl-phosphate synthetase large chain, oligomerisation domain
CPSase_L_D1PF25596.2 6.4e-44565–684 Carbamoyl phosphate synthase preATP-grasp domain
Dala_Dala_lig_CPF07478.19 1.6e-05695–856 D-ala D-ala ligase C-terminus
ATP-graspPF02222.28 5.2e-08696–860 ATP-grasp domain
MGSPF02142.28 8.7e-23986–1078 MGS-like 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:774 coexpression:967 experimental:928 database:900 textmining:453
Rv1380 pyrB aspartate carbamoyltransferase 999 1000 ctx neighborhood:882 fusion:900 cooccurence:508 coexpression:861 database:900 textmining:860
Rv1381 pyrC dihydroorotase 999 999 ctx neighborhood:882 fusion:900 coexpression:868 textmining:753
Rv1385 pyrF orotidine 5'-phosphate decarboxylase 998 997 ctx neighborhood:881 fusion:653 coexpression:918 textmining:419
Rv1382 hyp hypothetical protein 996 995 ctx neighborhood:882 coexpression:793 experimental:829
Rv1658 argG argininosuccinate synthase 995 988 ctx fusion:720 coexpression:794 database:800 textmining:651
Rv1656 argF ornithine carbamoyltransferase 992 979 ctx fusion:818 coexpression:431 database:800 textmining:657
Rv1379 pyrR bifunctional pyrimidine operon regulatory protein/uracil phosphoribosyltransferase 982 976 ctx neighborhood:882 coexpression:809
Rv0808 purF amidophosphoribosyltransferase 981 975 coexpression:665 database:900
Rv3859c gltB glutamate synthase large subunit 991 971 ctx neighborhood:544 coexpression:407 database:900 textmining:730
Rv3436c glmS glucosamine--fructose-6-phosphate aminotransferase 937 919 database:900
Rv2139 pyrD dihydroorotate dehydrogenase 949 917 coexpression:858 textmining:412
Rv2222c glnA2 glutamine synthetase 923 917 database:900
Rv0788 purQ phosphoribosylformylglycinamidine synthase 933 910 database:900
Rv3858c gltD glutamate synthase small subunit 930 907 database:900

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): carbamoyl-phosphate synthase large subunit
  • Pfam (hmmscan --cut_ga): CPSase_L_D2 PF02786.23 (E=2e-65), CPSase_L_D3 PF02787.26 (E=3e-21), CPSase_L_D1 PF25596.2 (E=6e-44), Dala_Dala_lig_C PF07478.19 (E=2e-05), ATP-grasp PF02222.28 (E=5e-08), MGS PF02142.28 (E=9e-23)
  • (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 YP_177804.1)
  • Domains: Pfam-A via hmmscan --cut_ga — CPSase_L_D2 (PF02786.23), CPSase_L_D3 (PF02787.26), CPSase_L_D1 (PF25596.2), Dala_Dala_lig_C (PF07478.19), ATP-grasp (PF02222.28), MGS (PF02142.28)
  • 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 COG0458
  • Curated reference: UniProt P9WPK3 (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 — 94 functional partner(s); context anchor carA
  • Primary literature: none located yet; annotation rests on the domain/homology sources above.

Ancestral MTBC0 protein sequence

>H37Rv|Rv1384|carB
MPRRTDLHHVLVIGSGPIVIGQACEFDYSGTQACRVLRAEGLQVSLVNSNPATIMTDPEFADHTYVEPITPAFVERVIAQQAERGNKIDALLATLGGQTALNTAVALYESGVLEKYGVELIGADFDAIQRGEDRQRFKDIVAKAGGESARSRVCFTMAEVRETVAELGLPVVVRPSFTMGGLGSGIAYSTDEVDRMAGAGLAASPSANVLIEESIYGWKEFELELMRDGHDNVVVVCSIENVDPMGVHTGDSVTVAPAMTLTDREYQRMRDLGIAILREVGVDTGGCNIQFAVNPRDGRLIVIEMNPRVSRSSALASKATGFPIAKIAAKLAIGYTLDEIVNDITGETPACFEPTLDYVVVKAPRFAFEKFPGADPTLTTTMKSVGEAMSLGRNFVEALGKVMRSLETTRAGFWTAPDPDGGIEEALTRLRTPAEGRLYDIELALRLGATVERVAEASGVDPWFIAQINELVNLRNELVAAPVLNAELLRRAKHSGLSDHQIASLRPELAGEAGVRSLRVRLGIHPVYKTVDTCAAEFEAQTPYHYSSYELDPAAETEVAPQTERPKVLILGSGPNRIGQGIEFDYSCVHAATTLSQAGFETVMVNCNPETVSTDYDTADRLYFEPLTFEDVLEVYHAEMESGSGGPGVAGVIVQLGGQTPLGLAHRLADAGVPIVGTPPEAIDLAEDRGAFGDLLSAAGLPAPKYGTATTFAQARRIAEEIGYPVLVRPSYVLGGRGMEIVYDEETLQGYITRATQLSPEHPVLVDRFLEDAVEIDVDALCDGAEVYIGGIMEHIEEAGIHSGDSACALPPVTLGRSDIAKVRKATEAIAHGIGVVGLLNVQYALKDDVLYVLEANPRASRTVPFVSKATAVPLAKACARIMLGATIAQLRAEGLLAVTGDGAHAARNAPIAVKEAVLPFHRFRRADGAAIDSLLGPEMKSTGEVMGIDRDFGSAFAKSQTAAYGSLPAQGTVFVSVANRDKRSLVFPVKRLADLGFRVLATEGTAEMLRRNGIPCDDVRKHFEPAQPGRPTMSAVDAIRAGEVNMVINTPYGNSGPRIDGYEIRSAAVAGNIPCITTVQGASAAVQGIEAGIRGDIGVRSLQELHRVIGGVER