Chloroplast transit peptides often require downstream unstructured sequence in Chlamydomonas reinhardtii

1 The N-terminal sequence stretch that defines subcellular targeting for most nuclear encoded chloroplast proteins is usually considered identical to the sequence that is cleaved upon import. Yet here this study shows that for nine out of ten tested Chlamydomonas chloroplast transit peptides, additional sequence past the cleavage site is required to enable chloroplast targeting. Using replacements of native post-cleavage residues with alternative sequences points to a role for unstructured sequence at mature protein N-termini.