Use the PlasmoAP algorithm to predict apicoplast-targeting signals.

Explanation

The apicoplast is a distintive subcellular structure, acquired when an ancestral protist 'ate' (or was invaded by) a eukaryotic alga, and retained the algal plastid. The apicoplast has lost photosynthetic function, but is nevertheless essential for parasite survival, and has generated considerable excitement as a potential drug target. Nuclear-encoded apicoplast proteins are imported into the organelle using a bipartite targeting signal consisting of a classical secretory signal sequence, followed by a plastid transit peptide.

PlasmoAP is a rules-based algorithm that uses amino-acid frequency and distribution to identify putative apicoplast-targeting peptides. Just paste a protein sequence into the text box above, and click on "Run". Note that this algorithm will predict target to the apicoplast only if a signal sequence is present. Also note that PlasmoAP performs well only for P. falciparum sequences, as A+T content skews amino acid distribution. For more information on this tool please click here, or see Foth, BJ et al. Science 299:5606 (2003).