CPA1/YOR303W Summary Help

Standard Name CPA1 1
Systematic Name YOR303W
Feature Type ORF, Verified
Description Small subunit of carbamoyl phosphate synthetase; carbamoyl phosphate synthetase catalyzes a step in the synthesis of citrulline, an arginine precursor; translationally regulated by an attenuator peptide encoded by YOR302W within the CPA1 mRNA 5'-leader (2, 3 and see Summary Paragraph)
Name Description Carbamyl Phosphate synthetase A 1
Chromosomal Location
ChrXV:882899 to 884134 | ORF Map | GBrowse
Genetic position: 161 cM
Gene Ontology Annotations All CPA1 GO evidence and references
  View Computational GO annotations for CPA1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 7 genes
Classical genetics
Large-scale survey
27 total interaction(s) for 21 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 13
  • Affinity Capture-RNA: 4
  • Affinity Capture-Western: 1
  • Two-hybrid: 1

Genetic Interactions
  • Dosage Rescue: 2
  • Negative Genetic: 2
  • Positive Genetic: 1
  • Synthetic Growth Defect: 3

Expression Summary
Length (a.a.) 411
Molecular Weight (Da) 45,361
Isoelectric Point (pI) 7.28
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrXV:882899 to 884134 | ORF Map | GBrowse
Genetic position: 161 cM
Last Update Coordinates: 2011-02-03 | Sequence: 1996-07-31
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..1236 882899..884134 2011-02-03 1996-07-31
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | E.C. | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Primary SGDIDS000005829

CPA1 encodes the small subunit of carbamoyl-phosphate synthase (glutamine-hydrolyzing) (also called arginine-specific carbamoyl-phosphate synthase) (2, 4, 5), a cytosolic enzyme in the arginine biosynthetic pathway (6). The small subunit, Cpa1p, binds and cleaves glutamine, while the large subunit, encoded by CPA2, binds the remaining substrates and carries out all other reactions catalyzed by the heterodimer (7). Interaction between Cpa1p and Cpa2p increases the Vmax of Cpa2p, perhaps by causing a conformational change in Cpa2p (7). Both transcription and translation of CPA1 are repressed in the presence of arginine (8, 9, 10, 11); the translational repression requires sequences within a small ORF (uORF) upstream of the coding sequence in the CPA1 mRNA (11). Yeast carbamoyl-phosphate synthase shares sequence similarity with heterodimeric and single subunit carbamoyl-phosphate synthases from E. coli and eukaryotes including rat, human, and hamster (2 4, 12, 7, 5). In humans, carbamoyl-phosphate synthase deficiency causes hyperammonemia (13).

Last updated: 1999-10-22 Contact SGD

References cited on this page View Complete Literature Guide for CPA1
1) Pierard A, et al.  (1979) Dual regulation of the synthesis of the arginine pathway carbamoylphosphate synthase of Saccharomyces cerevisiae by specific and general controls of amino acid biosynthesis. Mol Gen Genet 174(2):163-71
2) Nyunoya H and Lusty CJ  (1984) Sequence of the small subunit of yeast carbamyl phosphate synthetase and identification of its catalytic domain. J Biol Chem 259(15):9790-8
3) Wang Z, et al.  (1999) A highly conserved mechanism of regulated ribosome stalling mediated by fungal arginine attenuator peptides that appears independent of the charging status of arginyl-tRNAs. J Biol Chem 274(53):37565-74
4) Werner M, et al.  (1985) Nucleotide sequence of yeast gene CP A1 encoding the small subunit of arginine-pathway carbamoyl-phosphate synthetase. Homology of the deduced amino acid sequence to other glutamine amidotransferases. Eur J Biochem 146(2):371-81
5) Bernard A, et al.  (1997) In vivo mutational analysis of highly conserved amino acid residues of the small subunit Cpa1p of the carbamylphosphate synthetase of Saccharomyces cerevisiae. Yeast 13(11):1021-8
6) Jauniaux JC, et al.  (1978) Arginine metabolism in Saccharomyces cerevisiae: subcellular localization of the enzymes. J Bacteriol 133(3):1096-1107
7) Lim AL and Powers-Lee SG  (1996) Requirement for the carboxyl-terminal domain of Saccharomyces cerevisiae carbamoyl-phosphate synthetase. J Biol Chem 271(19):11400-9
8) Werner M, et al.  (1987) The leader peptide of yeast gene CPA1 is essential for the translational repression of its expression. Cell 49(6):805-13
9) Crabeel M, et al.  (1990) Arginine-specific repression in Saccharomyces cerevisiae: kinetic data on ARG1 and ARG3 mRNA transcription and stability support a transcriptional control mechanism. Mol Cell Biol 10(3):1226-33
10) Hinnebusch A  (1992) "General and Pathway-specific Regulatory Mechanisms Controlling the Synthesis of Amino Acid Biosynthetic Enzymes in Saccharomyces cerevisiae". Pp. 319-414 in The Molecular and Cellular Biology of the Yeast Saccharomyces: Gene Expression, edited by Jones EW, Pringle JR and Broach JR. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory Press
11) Delbecq P, et al.  (1994) A segment of mRNA encoding the leader peptide of the CPA1 gene confers repression by arginine on a heterologous yeast gene transcript. Mol Cell Biol 14(4):2378-90
12) Nyunoya H, et al.  (1985) Characterization and derivation of the gene coding for mitochondrial carbamyl phosphate synthetase I of rat. J Biol Chem 260(16):9346-56
13) Foury F  (1997) Human genetic diseases: a cross-talk between man and yeast. Gene 195(1):1-10