Fig. 3

Post-translational modifications of proteins in Cyclospora cayetanensis and other apicomplexans. a Core structure of GPI-anchor precursor and critical enzymes involved in its biosynthesis. Genes encoding PIG-V and PIG-B (shown in red) are absent in the C. cayetanensis genome. b Structure of hypothetical N-glycan precursors in different apicomplexans. Due to the secondary loss of ALG-encoding genes, the precursors of N-glycan are divergent in apicomplexans from 10 sugars in Toxoplasma gondii to 2 sugars in Plasmodium falciparum and Eimeria tenella. C. cayetanensis possesses a 7 sugar precursor which is just enough for glycosylation but not sufficient for N-glycan-dependent quality control of protein folding. c Phylogenetic relationship of ppGalNAc-Ts, the critical enzyme in mucin-type O-glycan biosynthesis, from Cryptosporidium parvum (Cp), T. gondii (Tg), E. tenella (ETH), and C. cayetanensis (cyc) based on a neighbor-joining analysis using genetic distances calculated with the maximum composite likelihood method. Numbers on branches are percent bootstrap values >50 from 1,000 replications. C. cayetanensis has ppGalNAc-Ts similar to other coccidia, especially E. tenella