UniProt:B9EXM2 CARB

chain
  • transit peptide:1-50
  • chain:51-1172
checksum 5DEF305423F90C63
comment
  • FUNCTION Large subunit of the arginine-specific carbamoyl phosphate synthase (CPSase). CPSase catalyzes the formation of carbamoyl phosphate from the ammonia moiety of glutamine, hydrogencarbonate, 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 which reacts with ammonia to form carbamoyl phosphate.CATALYTIC ACTIVITY hydrogencarbonate + L-glutamine + 2 ATP + H2O = carbamoyl phosphate + L-glutamate + 2 ADP + phosphate + 2 H(+)CATALYTIC ACTIVITY hydrogencarbonate + NH4(+) + 2 ATP = carbamoyl phosphate + 2 ADP + phosphate + 2 H(+)COFACTOR Binds 4 Mg(2+) or Mn(2+) ions per subunit.PATHWAY Amino-acid biosynthesis; L-arginine biosynthesis; carbamoyl phosphate from bicarbonate: step 1/1.SUBUNIT Heterodimer composed of 2 chains; the small (or glutamine) chain promotes the hydrolysis of glutamine to ammonia, which is used by the large (or ammonia) chain to synthesize carbamoyl phosphate.SUBCELLULAR LOCATION The large subunit is composed of 2 ATP-grasp domains that are involved in binding the 2 ATP molecules needed for carbamoyl phosphate synthesis. The N-terminal ATP-grasp domain (referred to as the carboxyphosphate synthetic component) catalyzes the ATP-dependent phosphorylation of hydrogencarbonate to carboxyphosphate and the subsequent nucleophilic attack by ammonia to form a carbamate intermediate. The C-terminal ATP-grasp domain (referred to as the carbamoyl phosphate synthetic component) then catalyzes the phosphorylation of carbamate with the second ATP to form the end product carbamoyl phosphate. The reactive and unstable enzyme intermediates are sequentially channeled from one active site to the next through the interior of the protein over a distance of at least 96 A.DOMAIN The C-terminal MGS-like domain is required for catalytic function.SIMILARITY Belongs to the CarB family.
created [InstanceEdit:5138379] D'Eustachio, P, 2013-11-14
databaseName UniProt
dbId 5138378
description
  • recommendedName: fullName evidence="8"Carbamoyl phosphate synthase arginine-specific large chain, chloroplastic shortName: CPS shortName: CPSase ecNumber evidence="2"6.3.4.16 ecNumber evidence="3"6.3.5.5 alternativeName: Ammonium-dependent carbamoyl phosphate synthetase alternativeName: Arginine-specific carbamoyl phosphate synthetase, ammonia chain alternativeName: Glutamine-dependent carbamoyl phosphate synthetase
displayName UniProt:B9EXM2 CARB
geneName
  • CARB
  • Os01g0570700
  • LOC_Os01g38970
  • OsJ_02282
identifier B9EXM2
isSequenceChanged false
keyword
  • Amino-acid biosynthesis
  • Arginine biosynthesis
  • ATP-binding
  • Chloroplast
  • Ligase
  • Magnesium
  • Manganese
  • Metal-binding
  • Nucleotide-binding
  • Plastid
  • Pyrimidine biosynthesis
  • Reference proteome
  • Repeat
  • Transit peptide
modified [InstanceEdit:9939033] Weiser, Joel, 2025-02-21
name
  • CARB
referenceDatabase [ReferenceDatabase:2] UniProt
schemaClass ReferenceGeneProduct
secondaryIdentifier
  • CARB_ORYSJ
  • Q0JLU1
sequenceLength 1172
species [Species:1250427] Oryza sativa subsp. japonica
url http://purl.uniprot.org/uniprot/B9EXM2