PYRG_AZOBR
ID PYRG_AZOBR Reviewed; 544 AA.
AC P28595;
DT 01-DEC-1992, integrated into UniProtKB/Swiss-Prot.
DT 01-DEC-1992, sequence version 1.
DT 03-AUG-2022, entry version 95.
DE RecName: Full=CTP synthase {ECO:0000255|HAMAP-Rule:MF_01227};
DE EC=6.3.4.2 {ECO:0000255|HAMAP-Rule:MF_01227};
DE AltName: Full=Cytidine 5'-triphosphate synthase {ECO:0000255|HAMAP-Rule:MF_01227};
DE AltName: Full=Cytidine triphosphate synthetase {ECO:0000255|HAMAP-Rule:MF_01227};
DE Short=CTP synthetase {ECO:0000255|HAMAP-Rule:MF_01227};
DE Short=CTPS {ECO:0000255|HAMAP-Rule:MF_01227};
DE AltName: Full=UTP--ammonia ligase {ECO:0000255|HAMAP-Rule:MF_01227};
GN Name=pyrG {ECO:0000255|HAMAP-Rule:MF_01227, ECO:0000305|PubMed:8138139};
OS Azospirillum brasilense.
OC Bacteria; Proteobacteria; Alphaproteobacteria; Rhodospirillales;
OC Azospirillaceae; Azospirillum.
OX NCBI_TaxID=192;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND FUNCTION.
RC STRAIN=ATCC 29145 / DSM 1690 / IMET 11303 / Sp7;
RX PubMed=8138139; DOI=10.1111/j.1574-6968.1994.tb06650.x;
RA Zimmer W., Hundeshagen B.;
RT "Identification and sequencing of pyrG, the CTP synthetase gene of
RT Azospirillum brasilense Sp7.";
RL FEMS Microbiol. Lett. 115:273-278(1994).
CC -!- FUNCTION: Catalyzes the ATP-dependent amination of UTP to CTP with
CC either L-glutamine or ammonia as the source of nitrogen
CC (PubMed:8138139). Regulates intracellular CTP levels through
CC interactions with the four ribonucleotide triphosphates (By
CC similarity). {ECO:0000255|HAMAP-Rule:MF_01227,
CC ECO:0000305|PubMed:8138139}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ATP + H2O + L-glutamine + UTP = ADP + CTP + 2 H(+) + L-
CC glutamate + phosphate; Xref=Rhea:RHEA:26426, ChEBI:CHEBI:15377,
CC ChEBI:CHEBI:15378, ChEBI:CHEBI:29985, ChEBI:CHEBI:30616,
CC ChEBI:CHEBI:37563, ChEBI:CHEBI:43474, ChEBI:CHEBI:46398,
CC ChEBI:CHEBI:58359, ChEBI:CHEBI:456216; EC=6.3.4.2;
CC Evidence={ECO:0000255|HAMAP-Rule:MF_01227};
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; Evidence={ECO:0000255|HAMAP-
CC Rule:MF_01227};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=ATP + NH4(+) + UTP = ADP + CTP + 2 H(+) + phosphate;
CC Xref=Rhea:RHEA:16597, ChEBI:CHEBI:15378, ChEBI:CHEBI:28938,
CC ChEBI:CHEBI:30616, ChEBI:CHEBI:37563, ChEBI:CHEBI:43474,
CC ChEBI:CHEBI:46398, ChEBI:CHEBI:456216; Evidence={ECO:0000255|HAMAP-
CC Rule:MF_01227};
CC -!- ACTIVITY REGULATION: Allosterically activated by GTP, when glutamine is
CC the substrate; GTP has no effect on the reaction when ammonia is the
CC substrate. The allosteric effector GTP functions by stabilizing the
CC protein conformation that binds the tetrahedral intermediate(s) formed
CC during glutamine hydrolysis. Inhibited by the product CTP, via
CC allosteric rather than competitive inhibition. {ECO:0000255|HAMAP-
CC Rule:MF_01227}.
CC -!- PATHWAY: Pyrimidine metabolism; CTP biosynthesis via de novo pathway;
CC CTP from UDP: step 2/2. {ECO:0000255|HAMAP-Rule:MF_01227}.
CC -!- SUBUNIT: Homotetramer. {ECO:0000255|HAMAP-Rule:MF_01227}.
CC -!- MISCELLANEOUS: CTPSs have evolved a hybrid strategy for distinguishing
CC between UTP and CTP. The overlapping regions of the product feedback
CC inhibitory and substrate sites recognize a common feature in both
CC compounds, the triphosphate moiety. To differentiate isosteric
CC substrate and product pyrimidine rings, an additional pocket far from
CC the expected kinase/ligase catalytic site, specifically recognizes the
CC cytosine and ribose portions of the product inhibitor.
CC {ECO:0000255|HAMAP-Rule:MF_01227}.
CC -!- SIMILARITY: Belongs to the CTP synthase family. {ECO:0000255|HAMAP-
CC Rule:MF_01227}.
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DR EMBL; X67216; CAA47656.1; -; Genomic_DNA.
DR PIR; I39496; S25101.
DR AlphaFoldDB; P28595; -.
DR SMR; P28595; -.
DR UniPathway; UPA00159; UER00277.
DR GO; GO:0005524; F:ATP binding; IEA:UniProtKB-KW.
DR GO; GO:0003883; F:CTP synthase activity; IEA:UniProtKB-UniRule.
DR GO; GO:0004359; F:glutaminase activity; IEA:RHEA.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:0044210; P:'de novo' CTP biosynthetic process; IEA:UniProtKB-UniPathway.
DR GO; GO:0006541; P:glutamine metabolic process; IEA:UniProtKB-KW.
DR CDD; cd03113; CTPS_N; 1.
DR CDD; cd01746; GATase1_CTP_Synthase; 1.
DR Gene3D; 3.40.50.300; -; 1.
DR Gene3D; 3.40.50.880; -; 1.
DR HAMAP; MF_01227; PyrG; 1.
DR InterPro; IPR029062; Class_I_gatase-like.
DR InterPro; IPR004468; CTP_synthase.
DR InterPro; IPR017456; CTP_synthase_N.
DR InterPro; IPR017926; GATASE.
DR InterPro; IPR033828; GATase1_CTP_Synthase.
DR InterPro; IPR027417; P-loop_NTPase.
DR PANTHER; PTHR11550; PTHR11550; 1.
DR Pfam; PF06418; CTP_synth_N; 1.
DR Pfam; PF00117; GATase; 1.
DR SUPFAM; SSF52317; SSF52317; 1.
DR SUPFAM; SSF52540; SSF52540; 1.
DR TIGRFAMs; TIGR00337; PyrG; 1.
DR PROSITE; PS51273; GATASE_TYPE_1; 1.
PE 3: Inferred from homology;
KW ATP-binding; Glutamine amidotransferase; Ligase; Magnesium; Metal-binding;
KW Nucleotide-binding; Pyrimidine biosynthesis.
FT CHAIN 1..544
FT /note="CTP synthase"
FT /id="PRO_0000138161"
FT DOMAIN 291..543
FT /note="Glutamine amidotransferase type-1"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT REGION 1..265
FT /note="Amidoligase domain"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT ACT_SITE 380
FT /note="Nucleophile; for glutamine hydrolysis"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT ACT_SITE 516
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT ACT_SITE 518
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 13
FT /ligand="CTP"
FT /ligand_id="ChEBI:CHEBI:37563"
FT /ligand_note="allosteric inhibitor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 13
FT /ligand="UTP"
FT /ligand_id="ChEBI:CHEBI:46398"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 14..19
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 54
FT /ligand="L-glutamine"
FT /ligand_id="ChEBI:CHEBI:58359"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 71
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 71
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 139
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 146..148
FT /ligand="CTP"
FT /ligand_id="ChEBI:CHEBI:37563"
FT /ligand_note="allosteric inhibitor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 186..191
FT /ligand="CTP"
FT /ligand_id="ChEBI:CHEBI:37563"
FT /ligand_note="allosteric inhibitor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 186..191
FT /ligand="UTP"
FT /ligand_id="ChEBI:CHEBI:46398"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 222
FT /ligand="CTP"
FT /ligand_id="ChEBI:CHEBI:37563"
FT /ligand_note="allosteric inhibitor"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 222
FT /ligand="UTP"
FT /ligand_id="ChEBI:CHEBI:46398"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 240
FT /ligand="ATP"
FT /ligand_id="ChEBI:CHEBI:30616"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 353
FT /ligand="L-glutamine"
FT /ligand_id="ChEBI:CHEBI:58359"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 381..384
FT /ligand="L-glutamine"
FT /ligand_id="ChEBI:CHEBI:58359"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 404
FT /ligand="L-glutamine"
FT /ligand_id="ChEBI:CHEBI:58359"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
FT BINDING 472
FT /ligand="L-glutamine"
FT /ligand_id="ChEBI:CHEBI:58359"
FT /evidence="ECO:0000255|HAMAP-Rule:MF_01227"
SQ SEQUENCE 544 AA; 59908 MW; 13AA1A8B8EB6C5DB CRC64;
MTRYIFITGG VVSSLGKGLA SAALGALLQA RGYKVRLAKL DPYLNVDPGT MSPYQHGEVY
VTDDGAETDL DLGHYERFTG VAARRGDNIT TGRIYSNVIA KERRGDYLGA TVQVIPHVTD
QIKDFIGAET TDEDFILCEI GGTVGDIEST PFLEAIRQFG NEVGPENALF IHLTLLPYIP
TAGELKTKPT QHSVKELLGM GIQANILLCR ADRPIPENER KKIALFCNIR PERVIAALDV
DSIYQVPVSY HEEGFDTQVL AYFGLPTEGK PDLSRWTSIV ERVRKPQGEV TIAVVGKYTS
LLDSYKSLAE ALTHGGIANN VKVKLDWIDS EIFEDESAVQ RLENVHGILV PGGFGSRGTE
GKIRAAQFAR ERKVPYFGIC FGMQMAVIES ARNMAGIVDA GSTELGKPGN PVVGLLGLMT
EWMRGNSLEK RTEGTDVGGT MRLGTYPAKL VPGSKVAEVY GTTDITERHR HRYEVNVYYK
DRLEKVGLLF SGLSPTQLPE IVEIPDHPWF IGVQFHPELK SKPFDPHPLF TSFIKAAIEQ
SRLV
