Toxoplasma gondii Sporozoites Invade Host Cells Using Two Novel Paralogues of RON2 and AMA1
Figure 3
SporoAMA1 presents a highly guarded apical groove.
A. Stacked three domain architecture of sporoAMA1 shown in the predicted organization to the T. gondii sporozoite plasma membrane with the three ectodomains indicated as DI in burgundy, DII in green and DIII in blue. Disulfides are shown as yellow sticks. Dotted line indicates extended Pro/Glu rich region between the conserved portion of DIII and the transmembrane domain (grey rectangle) that leads through to the C-terminal domain (grey oval). B. Apical view of apo sporoAMA1 structure, with core structure shown as grey surface and DI surface loops that guard the apical groove shown as burgundy cartoon and semi-transparent surfaces, and the DII loop as a green cartoon and semi-transparent surface. N-linked glycosylation on Asn230 shown as sticks. Numbers indicate surface loops that frame the apical groove. Inset: sporoAMA1 DII loop residues Phe376 and Trp377 (green) are pinned into the apical groove by Pro227 at the tip of loop 2 (burgundy).