Predicting parasite metabolic networks: A fisherman's nightmare?

Mapping the complete metabolic networks (i.e. all of the biochemical pathways encoded in the genome) of parasites will enhance our understanding of evolution of obligate parasites and permit prediction of novel drug targets. Yet many biochemical pathways predicted in the annotated genomes are incomplete. This may be due to poor homology with known enzymes, loss of pathways, or alternative pathways. Applying our metaSHARK software package we have assessed the completeness of several metabolic pathways in the genomes of Plasmodium, Theileria, Cryptosporidium, Entamoeba, and trypanosomes. The overall completeness of the P. falciparum metabolic network is substantially lower than yeast or E. coli which may be related to adaptation to a parasitic life style.