ID   CARA_PORPU              Reviewed;         384 AA.
AC   P51201;
DT   01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-1996, sequence version 1.
DT   25-MAY-2022, entry version 105.
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   Porphyra purpurea (Red seaweed) (Ulva purpurea).
OG   Plastid; Chloroplast.
OC   Eukaryota; Rhodophyta; Bangiophyceae; Bangiales; Bangiaceae; Porphyra.
OX   NCBI_TaxID=2787;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Avonport;
RA   Reith M.E., Munholland J.;
RT   "Complete nucleotide sequence of the Porphyra purpurea chloroplast
RT   genome.";
RL   Plant Mol. Biol. Rep. 13:333-335(1995).
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; U38804; AAC08087.1; -; Genomic_DNA.
DR   PIR; S73122; S73122.
DR   RefSeq; NP_053811.1; NC_000925.1.
DR   AlphaFoldDB; P51201; -.
DR   SMR; P51201; -.
DR   GeneID; 809825; -.
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..384
FT                   /note="Carbamoyl-phosphate synthase small chain"
FT                   /id="PRO_0000112371"
FT   DOMAIN          196..382
FT                   /note="Glutamine amidotransferase type-1"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
FT   REGION          1..192
FT                   /note="CPSase"
FT   ACT_SITE        272
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
FT   ACT_SITE        355
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
FT   ACT_SITE        357
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01209"
SQ   SEQUENCE   384 AA;  43296 MW;  D0C45C21FB28E56B CRC64;
     MIKKIPAILV LEDGTYYKGW SFQADQSIVT IGEVVFNTGM TGYQEIITDP SYFQQIVTFT
     YPEIGNTGIN SEDIESQTIS IKGLVAKNIC KISSSWRQQE SLVQYLNRYK IPFIFGIDTR
     SLTQYLRRSG TMNGCISNKN LNHAYLQRKI SEVPHMTGLD LIPNVTTNIM YDWDEKSLPS
     WYLADRNREK IYSQLKVIVI DFGVKLNILR RLATLGCQIT VMPASTPTQD ILSCKPDGIL
     LSNGPGDPSA VNYGIKTVKE LLNQNIPIFG ICMGHQILNL ALEAKTFKLK FGHRGINHPS
     GLKQQVEITS QNHGFAVDLQ SVLKLSLQVT HFNLNDITVA GTGHSRSPYF SVQYHPESSP
     GPHDADYLFE YFIEIMKQFR KEAN