FIG. 6.

Domain organizations of extracellular proteins with architectures that are shared between Ascogregarina, Cryptosporidium, and Toxoplasma to the exclusion of Plasmodium and Theileria (A) or conserved among all apicomplexans (B). All proteins have a signal peptide, indicated by a yellow box at the amino terminus. Domains present within the protein architectures include: Tox1 (ShKT); Notch (NL); TSP1; Sushi (CCP); ARC; MAM; Cu-amine oxidase (Cu_amine_oxidase); Glycotransferase-1 (glycos_transf_1); Ricin; Cys; Discoidin (F5_F8_type_C); NEC; LCCL; Levanase; ApiECA; LH2 (PLAT_SR); SR; Pentraxin (PTX); and transmembrane domains (TM). Many of these domains are described further at one of the following browsers of domains: http://smart.embl-heidelberg.de/browse.shtml and http://pfam.janelia.org/browse.shtml. Not described in these browsers is the Cys domain found in the highly cysteine-rich coccidian oocyst–wall proteins and the ARC domain that is a small domain with characteristically spaced cysteine residues that is fused to a papain-like protease domain in the secreted protein AF1946 from the archaean, Archaeoglobus fulgidus.