ID   CARA_CYACA              Reviewed;         399 AA.
AC   O19886;
DT   01-JUN-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-JAN-1998, sequence version 1.
DT   25-MAY-2022, entry version 107.
DE   RecName: Full=Carbamoyl-phosphate synthase small chain {ECO:0000255|HAMAP-Rule:MF_01209};
DE            EC=6.3.5.5 {ECO:0000255|HAMAP-Rule:MF_01209};
DE   AltName: Full=Carbamoyl-phosphate synthetase glutamine chain {ECO:0000255|HAMAP-Rule:MF_01209};
GN   Name=carA {ECO:0000255|HAMAP-Rule:MF_01209};
OS   Cyanidium caldarium (Red alga).
OG   Plastid; Chloroplast.
OC   Eukaryota; Rhodophyta; Bangiophyceae; Cyanidiales; Cyanidiaceae; Cyanidium.
OX   NCBI_TaxID=2771;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=RK-1;
RX   PubMed=11040290; DOI=10.1007/s002390010101;
RA   Gloeckner G., Rosenthal A., Valentin K.-U.;
RT   "The structure and gene repertoire of an ancient red algal plastid
RT   genome.";
RL   J. Mol. Evol. 51:382-390(2000).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=2 ATP + H2O + hydrogencarbonate + L-glutamine = 2 ADP +
CC         carbamoyl phosphate + 2 H(+) + L-glutamate + phosphate;
CC         Xref=Rhea:RHEA:18633, ChEBI:CHEBI:15377, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:17544, ChEBI:CHEBI:29985, ChEBI:CHEBI:30616,
CC         ChEBI:CHEBI:43474, ChEBI:CHEBI:58228, ChEBI:CHEBI:58359,
CC         ChEBI:CHEBI:456216; EC=6.3.5.5; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_01209};
CC   -!- PATHWAY: Amino-acid biosynthesis; L-arginine biosynthesis; carbamoyl
CC       phosphate from bicarbonate: step 1/1. {ECO:0000255|HAMAP-
CC       Rule:MF_01209}.
CC   -!- PATHWAY: Pyrimidine metabolism; UMP biosynthesis via de novo pathway;
CC       (S)-dihydroorotate from bicarbonate: step 1/3. {ECO:0000255|HAMAP-
CC       Rule:MF_01209}.
CC   -!- SUBUNIT: Composed of two chains; the small (or glutamine) chain
CC       promotes the hydrolysis of glutamine to ammonia, which is used by the
CC       large (or ammonia) chain to synthesize carbamoyl phosphate.
CC       {ECO:0000255|HAMAP-Rule:MF_01209}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast.
CC   -!- SIMILARITY: Belongs to the CarA family. {ECO:0000255|HAMAP-
CC       Rule:MF_01209}.
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DR   EMBL; AF022186; AAB82703.1; -; Genomic_DNA.
DR   PIR; T11954; T11954.
DR   RefSeq; NP_045058.1; NC_001840.1.
DR   AlphaFoldDB; O19886; -.
DR   SMR; O19886; -.
DR   GeneID; 800256; -.
DR   UniPathway; UPA00068; UER00171.
DR   UniPathway; UPA00070; UER00115.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
DR   GO; GO:0005524; F:ATP binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0004088; F:carbamoyl-phosphate synthase (glutamine-hydrolyzing) activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0006207; P:'de novo' pyrimidine nucleobase biosynthetic process; IEA:InterPro.
DR   GO; GO:0044205; P:'de novo' UMP biosynthetic process; IEA:UniProtKB-UniPathway.
DR   GO; GO:0006526; P:arginine biosynthetic process; IEA:UniProtKB-UniRule.
DR   GO; GO:0006541; P:glutamine metabolic process; IEA:UniProtKB-KW.
DR   CDD; cd01744; GATase1_CPSase; 1.
DR   Gene3D; 3.40.50.880; -; 1.
DR   Gene3D; 3.50.30.20; -; 1.
DR   HAMAP; MF_01209; CPSase_S_chain; 1.
DR   InterPro; IPR006274; CarbamoylP_synth_ssu.
DR   InterPro; IPR002474; CarbamoylP_synth_ssu_N.
DR   InterPro; IPR036480; CarbP_synth_ssu_N_sf.
DR   InterPro; IPR029062; Class_I_gatase-like.
DR   InterPro; IPR035686; CPSase_GATase1.
DR   InterPro; IPR017926; GATASE.
DR   Pfam; PF00988; CPSase_sm_chain; 1.
DR   Pfam; PF00117; GATase; 1.
DR   SMART; SM01097; CPSase_sm_chain; 1.
DR   SUPFAM; SSF52021; SSF52021; 1.
DR   SUPFAM; SSF52317; SSF52317; 1.
DR   TIGRFAMs; TIGR01368; CPSaseIIsmall; 1.
DR   PROSITE; PS51273; GATASE_TYPE_1; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis; Arginine biosynthesis; ATP-binding; Chloroplast;
KW   Glutamine amidotransferase; Ligase; Nucleotide-binding; Plastid;
KW   Pyrimidine biosynthesis.
FT   CHAIN           1..399
FT                   /note="Carbamoyl-phosphate synthase small chain"
FT                   /id="PRO_0000112369"
FT   DOMAIN          213..399
FT                   /note="Glutamine amidotransferase type-1"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
FT   REGION          1..209
FT                   /note="CPSase"
FT   ACT_SITE        289
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
FT   ACT_SITE        372
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
FT   ACT_SITE        374
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
SQ   SEQUENCE   399 AA;  45519 MW;  3BFDBB74FFA9218A CRC64;
     MEKFKLLKLG KPATLLLEDG TVFRGKSFSN PQTVTGEIVF NTGMTGYQEI FTDPSYNEQL
     VVLTYPEIGN TGTNLDDYES LKIQAKGIIL KNLSNAYSNF RAMRSLLSFL KRHKVVEIHD
     IDTRALVLHI RNNKTMLAVI SNETYNLTFK EAKATIKYGK HTLNSNLASR VSTSLDYYQW
     MQPLNRKLKF GYSIIRSFNS AINKKLHTSK KLRIIVLDLG VKFNILRYLK SFECEVIIVN
     YKSTYQQVMK FHPDGIVISN GPGDPAKINR VVVRVNKFIN KKIPILGICL GHQILARCFE
     AKTFKLKFGH RGLNHPVGIN KRMEITSQNH GFAVNFEFLK SNKFYANHLN LNDGTLAGIS
     SQNFPLISVQ YHPEGSPGPH DSNYLFKYWV YIIYKSKSS