Chaperone-assisted post-translational transport of plastidic type i signal peptidase 1

Abstract

Background: In bacteria, type I signal peptidase is targeted to the membrane co-translationally. Results: Plastidic type I signal peptidase 1 (Plsp1) could insert into the membrane in an incorrect orientation, which was prevented by a stroma chaperone and the cpSec1 machine. Conclusion: Correct membrane insertion of Plsp1 is ensured by stromal components. Significance: The results demonstrate an adaptive mechanism of protein transport during organelle evolution.