Colocalization of GFP constructs with endogenous ACP. αACP antibodies were affinity purified with the mature ACP domain to avoid cross-reactivity with the TP of ACP used in GFP fusions (26). GFP fluorescence was found to colocalize with αACP antibodies, demonstrating apicoplast localization. Scale bar = 2 μm. The 6PxxP mutation completely prohibits the formation of secondary structure in the TP. The 9PxxP construct disrupts secondary structure in the TP and the intervening region simultaneously without affecting protein localization. Substitution of 6 out of the 24 TP residues without perturbing trafficking to the apicoplast illustrates dramatic plasticity in TP recognition.

Gallagher JR, Matthews KA, Prigge ST. Plasmodium falciparum apicoplast transit peptides are unstructured in vitro and during apicoplast import. Traffic. 2011 12(9):1124-38.