ID   HIS5_CYACA              Reviewed;         214 AA.
AC   Q9TLQ8;
DT   01-JUN-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   25-MAY-2022, entry version 88.
DE   RecName: Full=Imidazole glycerol phosphate synthase subunit hisH;
DE            EC=4.3.2.10;
DE   AltName: Full=IGP synthase glutaminase subunit;
DE            EC=3.5.1.2;
DE   AltName: Full=IGP synthase subunit hisH;
DE   AltName: Full=ImGP synthase subunit hisH;
DE            Short=IGPS subunit hisH;
GN   Name=hisH;
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   -!- FUNCTION: IGPS catalyzes the conversion of PRFAR and glutamine to IGP,
CC       AICAR and glutamate. The HisH subunit catalyzes the hydrolysis of
CC       glutamine to glutamate and ammonia as part of the synthesis of IGP and
CC       AICAR. The resulting ammonia molecule is channeled to the active site
CC       of HisF (By similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=5-[(5-phospho-1-deoxy-D-ribulos-1-ylimino)methylamino]-1-(5-
CC         phospho-beta-D-ribosyl)imidazole-4-carboxamide + L-glutamine = 5-
CC         amino-1-(5-phospho-beta-D-ribosyl)imidazole-4-carboxamide + D-
CC         erythro-1-(imidazol-4-yl)glycerol 3-phosphate + H(+) + L-glutamate;
CC         Xref=Rhea:RHEA:24793, ChEBI:CHEBI:15378, ChEBI:CHEBI:29985,
CC         ChEBI:CHEBI:58278, ChEBI:CHEBI:58359, ChEBI:CHEBI:58475,
CC         ChEBI:CHEBI:58525; EC=4.3.2.10;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=H2O + L-glutamine = L-glutamate + NH4(+);
CC         Xref=Rhea:RHEA:15889, ChEBI:CHEBI:15377, ChEBI:CHEBI:28938,
CC         ChEBI:CHEBI:29985, ChEBI:CHEBI:58359; EC=3.5.1.2;
CC   -!- PATHWAY: Amino-acid biosynthesis; L-histidine biosynthesis; L-histidine
CC       from 5-phospho-alpha-D-ribose 1-diphosphate: step 5/9.
CC   -!- SUBUNIT: Heterodimer of hisH and hisF. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Plastid, chloroplast.
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DR   EMBL; AF022186; AAF12883.1; -; Genomic_DNA.
DR   RefSeq; NP_045211.1; NC_001840.1.
DR   AlphaFoldDB; Q9TLQ8; -.
DR   SMR; Q9TLQ8; -.
DR   GeneID; 800113; -.
DR   UniPathway; UPA00031; UER00010.
DR   GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
DR   GO; GO:0004359; F:glutaminase activity; IEA:UniProtKB-EC.
DR   GO; GO:0000107; F:imidazoleglycerol-phosphate synthase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0016829; F:lyase activity; IEA:UniProtKB-KW.
DR   GO; GO:0006541; P:glutamine metabolic process; IEA:UniProtKB-KW.
DR   GO; GO:0000105; P:histidine biosynthetic process; IEA:UniProtKB-UniRule.
DR   CDD; cd01748; GATase1_IGP_Synthase; 1.
DR   Gene3D; 3.40.50.880; -; 1.
DR   HAMAP; MF_00278; HisH; 1.
DR   InterPro; IPR029062; Class_I_gatase-like.
DR   InterPro; IPR017926; GATASE.
DR   InterPro; IPR010139; Imidazole-glycPsynth_HisH.
DR   PANTHER; PTHR42701; PTHR42701; 1.
DR   Pfam; PF00117; GATase; 1.
DR   PIRSF; PIRSF000495; Amidotransf_hisH; 1.
DR   SUPFAM; SSF52317; SSF52317; 1.
DR   TIGRFAMs; TIGR01855; IMP_synth_hisH; 1.
DR   PROSITE; PS51273; GATASE_TYPE_1; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis; Chloroplast; Glutamine amidotransferase;
KW   Histidine biosynthesis; Hydrolase; Lyase; Plastid.
FT   CHAIN           1..214
FT                   /note="Imidazole glycerol phosphate synthase subunit hisH"
FT                   /id="PRO_0000152471"
FT   DOMAIN          3..214
FT                   /note="Glutamine amidotransferase type-1"
FT   ACT_SITE        83
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        195
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        197
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   214 AA;  24305 MW;  24F3350FA195E06D CRC64;
     MKNIGIINCG MGNLHSVSNA ISNIGFNPVI INASKDLVSF ACSALVLPGV GSFDLAIDRL
     EKKNLIEPVK LWIQEDRPFV GICLGLQLLF EGSDEGSKPG LKIFNGYVSQ FKHSLVKKVP
     HMGWNKLYFN RFNTIDNLVP HYFHYDLQPW AYFVHSYYIE PKDCYTFNTT SLTFYGKQKI
     VSSISYNNIL ATQFHPEKSG LFGLFILKRF LSSY