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.- BBOV_III004000
S-adenosyl-methyltransferase 2.1.1.- BBOV_IV000910
Homocysteine S-methyltransferase 2.1.1.10 Missing in annotation
Methionine adenosyl transferase 2.5.1.6 BBOV_III009750
Adenosylhomocysteinase 3.3.1.1 BBOV_I001740
Adenosine deaminase 3.5.4.4 BBOV_II001470
Met-tRNA ligase 6.1.1.10 BBOV_I001970
tRNA binding protein none BBOV_III010240

 

List of genes annotated as tRNA-Met in B. bovis genome

 

BBOV_II001820 BBOV_II005320 BBOV_V000070
BBOV_V000520    

 

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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 Babesia bovis genome

 

Enzyme EC Number Gene id
DNA (cytosine-5-)-methyltransferase 2.1.1.37 BBOV_II004490
mRNA(2'-D-methyladenosine-N6)-methyltransferase 2.1.1.62 BBOV_III001900
mRNA(2'-D-methyladenosine-N6)-methyltransferase 2.1.1.62 BBOV_IV007610