Disease relevance of ECs3640

• The pyrG gene of Lactococcus lactis subsp. cremoris, encoding CTP synthase, has been cloned and sequenced [1].
• Escherichia coli CTP synthase, overexpressed as a hexahistidine-tagged form, was purified to high specific activity with the use of metal-ion-affinity chromatography [2].

Psychiatry related information on ECs3640

• Although the activation of CTP synthase by GTP does not display cooperative behavior, inhibition of both CTP synthase-catalyzed ammonia- and glutamine-dependent CTP synthesis by GTP do exhibit positive cooperativity [3].

High impact information on ECs3640

• Overall, the kinetic properties of L109A CTP synthase were consistent with an uncoupling of glutamine hydrolysis from CTP formation that occurs because an NH(3) tunnel has its normal structure altered or fails to form [4].
• Aspartate-107 and leucine-109 facilitate efficient coupling of glutamine hydrolysis to CTP synthesis by Escherichia coli CTP synthase [4].
• In an attempt to identify nucleotide-binding sites, scanning alanine mutagenesis was conducted on a highly conserved region of amino acid sequence (residues 102-118) within the synthase domain of Escherichia coli CTP synthase [4].
• Indeed, glutamate gamma-semialdehyde is a potent linear mixed-type inhibitor of CTP synthase with respect to glutamine (K(is) 0.16+/-0.03 mM; K(ii) 0.4+/-0.1 mM) and a competitive inhibitor with respect to ammonia (K(i) 0.39+/-0.06 mM) in the presence of GTP at pH 8 [2].
• Glutamate gamma-semialdehyde is expected to inhibit CTP synthase by reacting reversibly with the active-site Cys-379 to form an analogue of a tetrahedral intermediate in glutamine hydrolysis [2].

Chemical compound and disease context of ECs3640

• Inhibition of Escherichia coli CTP synthase by glutamate gamma-semialdehyde and the role of the allosteric effector GTP in glutamine hydrolysis [2].
• The role of lysine residues 297 and 306 in nucleoside triphosphate regulation of E. coli CTP synthase: inactivation by 2',3'-dialdehyde ATP and mutational analyses [5].

Biological context of ECs3640

• An incomplete open reading frame located 432 bp 5' of eno was identified as pyrG, which encodes CTP synthase [6].

Associations of ECs3640 with chemical compounds

• Unfused CTP synthase, generated by the enzymic removal of the hexahistidine tag, displayed an activity identical with that of the purified native enzyme and was used to study the effect of GTP on the inhibition of enzymic activity by glutamate gamma-semialdehyde [2].
• We show that the uncoupling of the hydrolysis of gamma-glutamyl hydroxamate and nascent NH(2)OH production from N(4)-hydroxy-CTP formation is more pronounced with the L109A enzyme, relative to the wild-type CTP synthase [7].

Analytical, diagnostic and therapeutic context of ECs3640

• Limited trypsin-catalysed proteolysis, Edman degradation, and site-directed mutagenesis were used to identify peptide bonds C-terminal to three basic residues (Lys187, Arg429, and Lys432) of Escherichia coli CTP synthase that were highly susceptible to proteolysis [8].

References