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Annotation rule MF_01227
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General rule information [?]

Accession MF_01227
Dates 20-SEP-2002 (Created)
12-JAN-2021 (Last updated, Version 32)
Name PyrG
Templates P0A7E5 (PYRG_ECOLI); P28595 (PYRG_AZOBR); Q59321 (PYRG_CHLTR); O87761 (PYRG_LACLM); P9WHK7 (PYRG_MYCTU); Q5SIA8 (PYRG_THET8); Q980S6 (PYRG_SACS2): [Recover all]

Propagated annotation [?]

Identifier, protein and gene names [?]

Protein name
RecName: Full=CTP synthase;
AltName: Full=Cytidine 5'-triphosphate synthase;
AltName: Full=Cytidine triphosphate synthetase;
Short=CTP synthetase;
AltName: Full=UTP--ammonia ligase;
Gene name

Comments [?]

Function Catalyzes the ATP-dependent amination of UTP to CTP with either L-glutamine or ammonia as the source of nitrogen. Regulates intracellular CTP levels through interactions with the four ribonucleotide triphosphates.
Catalytic activity RHEA:26426: ATP + H2O + L-glutamine + UTP = ADP + CTP + 2 H(+) + L-glutamate + phosphate
Activity regulation Allosterically activated by GTP, when glutamine is the substrate; GTP has no effect on the reaction when ammonia is the substrate. The allosteric effector GTP functions by stabilizing the protein conformation that binds the tetrahedral intermediate(s) formed during glutamine hydrolysis. Inhibited by the product CTP, via allosteric rather than competitive inhibition.
Pathway Pyrimidine metabolism; CTP biosynthesis via de novo pathway; CTP from UDP: step 2/2.
Subunit Homotetramer.
Miscellaneous CTPSs have evolved a hybrid strategy for distinguishing between UTP and CTP. The overlapping regions of the product feedback inhibitory and substrate sites recognize a common feature in both compounds, the triphosphate moiety. To differentiate isosteric substrate and product pyrimidine rings, an additional pocket far from the expected kinase/ligase catalytic site, specifically recognizes the cytosine and ribose portions of the product inhibitor.
Similarity Belongs to the CTP synthase family.

Keywords [?]

Gene Ontology [?]

GO:0003883; Molecular function: CTP synthase activity.
GO:0006221; Biological process: pyrimidine nucleotide biosynthetic process.

Cross-references [?]

Pfam PF06418; CTP_synth_N; 1;
PF00117; GATase; 1;
TIGRFAMs TIGR00337; PyrG; 1;
PROSITE PS51273; GATASE_TYPE_1; 1; trigger=PRU00605;

Features [?]

Key     From     To       Description   Tag   Condition   FTGroup
NP_BIND     15     20       ATP     x-x-G-K-G-x  
NP_BIND     147     149       CTP; allosteric inhibitor     D-x-E  
NP_BIND     187     192       CTP; allosteric inhibitor; alternate     K-[TS]-K-x-x-Q  
NP_BIND     187     192       UTP; alternate     K-[TS]-K-x-x-Q  
NP_BIND (Optional)     239     241       ATP; via amide nitrogen     [KR]-x-[VALI]  
case not <FT:5>
BINDING (Optional)     241     241       ATP     [VALI]  
end case
REGION     Nter     266       Amidoligase domain        
REGION     380     383       L-glutamine binding     [LMYF]-x-x-[QH]  
ACT_SITE     379     379       Nucleophile; for glutamine hydrolysis     C  
ACT_SITE     515     515             H  
ACT_SITE     517     517             E  
METAL     72     72       Magnesium     D  
METAL     140     140       Magnesium     E  
BINDING     14     14       CTP; allosteric inhibitor; alternate     S  
BINDING     14     14       UTP; alternate     S  
BINDING (Optional)     55     55       L-glutamine     Y  
BINDING     72     72       ATP     D  
BINDING     223     223       CTP; allosteric inhibitor; alternate     [KR]  
BINDING     223     223       UTP; alternate     [KR]  
BINDING     352     352       L-glutamine; via carbonyl oxygen     [GA]  
BINDING     403     403       L-glutamine     E  
BINDING     470     470       L-glutamine; via amide nitrogen     R  

Additional information [?]

Size range 524-608 amino acids
Related rules None
Fusion None
Comments RPE1 type insert in RICPR and weird insertion in TREPA; sequences not shown in alignment. Divergent UREPA; sequence not included in alignment.