Glutamate metabolism

Glutamate and glutamine are non-essential amino acids in both Toxoplasma gondii and Plasmodium falciparum as in humans, whereas glutamine is an essential amino acid utilised from host in Piroplasma species. This is because glutamine synthetase ezyme which catalyses glutamate to glutamine conversion is absent in these Piroplasma species. The favourable ecological niches of these parasites within hosts and the absence of parasitophorous vacuoles provide these parasites with the advantage of their ability to fulfil several amino acid requirements including asparagine, glutamine and proline from the host. The activity of aspartate transaminase enzyme of this pathway was assayed by Kiama et al in Theileria parva schizont and transamination of oxaloacetate with glutamate plays an important role in the carbon metabolism of this parasite [1].

 

Enzyme EC Number Gene id
Glutamate dehydrogenase (NAD-specific) 1.4.1.2 TA11105
Glutamate dehydrogenase (NADP-specific) 1.4.1.4 Missing in annotation (Absent)
Glutaminyl-peptide cyclotransferase 2.3.2.5 Missing in annotation (Absent)
Aspartate transaminase 2.6.1.1 TA12970
Hexosephosphate aminotransferase 2.6.1.16 TA15930
Glutamyl-tRNA synthetase 6.1.1.17 TA06725
Glutamyl-tRNA synthetase 6.1.1.17 TA17035
Glutaminyl-tRNA synthetase 6.1.1.18 TA12530
gamma-Glutamylcysteine synthetase 6.3.2.2 TA03765
Carbamoyl-phosphate synthase Glu synthesizing 6.3.5.5 TA02545
Glutamyl-tRNA(Gln) amidotransferase 6.3.5.7 TA19745

 

List of genes annotated as tRNA-Glu in T. annulata genome

 

TA16067 TA16088

 

List of genes annotated as tRNA-Gln in T. annulata genome

 

TA05303 TA05313

 

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Sources and fates of metabolites

 

Substrate Source pathways Product Fate pathways
D-Fructose-6P Glycolysis Oxaloacetate Pyruvate metabolism, Tricarboxylic acid (TCA) cycle
Glutamine Host 2-oxoglutarate Tricarboxylic acid (TCA) cycle
    gamma-glutamylcysteine Redox metabolism
    Glucosamine-6P Aminosugars metabolism
    Carbamoyl-P Pyrimidine metabolism