Methionine metabolism

Methionine, an essential amino acid in humans is also essential to all apicomplexans and need to be salvaged from the host. The methionine metabolism pathway in Piroplasma is essential for providing S-adenosylmethionine, the methyl group donor in various reactions. A metabolic capability which is present in Plasmodium falciparum and absent in Coccidia and Piroplasma is the synthesis of polyamines such as spermine and spermidine. This has been incorporated with methionine metabolism in MPMP (methionine and polyamine metabolism). The genes coding for the enzymes ornithine decarboxylase, arginine decarboxylase and spermine/spermidine synthase are absent in the genomes of Piroplasma. The back conversion of putrescine from spermine present in Coccidia is also absent in Piroplasma.


Enzyme EC Number Gene id
S-adenosyl-methyltransferase 2.1.1.- TA02665
S-adenosyl-methyltransferase 2.1.1.- TA18940
Homocysteine S-methyltransferase Missing in annotation
Methionine adenosyl transferase TA11070
Adenosylhomocysteinase TA05430
Met-tRNA ligase TA05325
Met-tRNA ligase TA09735
tRNA binding protein none TA11475


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


TA08228 TA15418


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Sources and fates of metabolites


Substrate Source pathways Product Fate pathways
Methionine Host Adenosine Purine metabolism


Examples of adenosylmethionine-dependent methyltransferases in Theileria annulata genome


Enzyme EC Number Gene id
DNA (cytosine-5-)-methyltransferase TA09075
mRNA(2'-D-methyladenosine-N6)-methyltransferase TA21155