ID   CARA_GRATL              Reviewed;         395 AA.
AC   Q6B940;
DT   21-JUN-2005, integrated into UniProtKB/Swiss-Prot.
DT   13-SEP-2004, sequence version 1.
DT   25-MAY-2022, entry version 81.
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}; OrderedLocusNames=Grc000013;
OS   Gracilaria tenuistipitata var. liui (Red alga).
OG   Plastid; Chloroplast.
OC   Eukaryota; Rhodophyta; Florideophyceae; Rhodymeniophycidae; Gracilariales;
OC   Gracilariaceae; Agarophyton; Agarophyton tenuistipitatum.
OX   NCBI_TaxID=285951;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=15638458; DOI=10.1007/s00239-004-2638-3;
RA   Hagopian J.C., Reis M., Kitajima J.P., Bhattacharya D., de Oliveira M.C.;
RT   "Comparative analysis of the complete plastid genome sequence of the red
RT   alga Gracilaria tenuistipitata var. liui provides insights into the
RT   evolution of rhodoplasts and their relationship to other plastids.";
RL   J. Mol. Evol. 59:464-477(2004).
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; AY673996; AAT79595.1; -; Genomic_DNA.
DR   RefSeq; YP_063520.1; NC_006137.1.
DR   AlphaFoldDB; Q6B940; -.
DR   SMR; Q6B940; -.
DR   GeneID; 2944065; -.
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..395
FT                   /note="Carbamoyl-phosphate synthase small chain"
FT                   /id="PRO_0000112370"
FT   DOMAIN          196..383
FT                   /note="Glutamine amidotransferase type-1"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
FT   REGION          1..192
FT                   /note="CPSase"
FT   ACT_SITE        273
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
FT   ACT_SITE        356
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
FT   ACT_SITE        358
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
SQ   SEQUENCE   395 AA;  45003 MW;  0F25E4FC7AC61739 CRC64;
     MTYNLHPAIL VLKDGKFYRG WTLINSIISF GEVVFNTGMT GYQEIMTDPS YAEQIITFTY
     PEIGNTGINH EDNESNKIHV KGIITKNICF SPNNWRQQES FINYIFNNQI PHIFGIDTRA
     LTKHLRKTGS MNGCISSQYL NPYLLSTKFK DRLSIESSDL VKQVTTSKNY EFQGYSHKHF
     SYLQYKTDKM YGYGLKIILI DFGVKYNILS RLDNYGCSIQ ILPATSSYET INAYNPDGII
     LSNGPGDPSI ITYAIKTVKK IIKYTNIPIF GICMGHQIIS LALEGTTFKL KFGHRGLNHP
     AGMKQKAEVT SQNHGFAVNQ ESLYKDTINI THFNLNDTTV AGILHNKKPI FSVQYHPEAS
     PGPHDSDYLF KYFINLIKHF KQYKNYKNSS LAQAR