Lysine is an essential amino acid in most Apicomplexa species as in humans and need to be utilised from host. The exception to this is the cyst forming Coccidians such as Toxoplasma gondii and Neospora caninum. The Cryptosporidia species possess the gene for the enzyme saccharopine dehydrogenase which converts lysine to saccharopine which can be degraded to 2-oxodipate in the host. The other enzymes involved in lysine degradation in Plasmodia and cyst forming Coccidia are absent in Cryptosporidia. This pathway also includes large number of genes coding histone-lysine N-methyltransferase which catalyses protein methylation.
|Enzyme||EC Number||Gene id|
List of genes annotated as tRNA-Lys in C. hominis genome
Sources and fates of metabolic pathways
|Substrate||Source pathways||Product||Fate pathways|