Researchers elucidate structure of enigmatic chloroplast protein transport machinery

Chloroplasts of algae and plants are the cellular engines that convert solar energy into chemical energy through photosynthesis. These organelles, bounded by an envelope with two membranes, contain their own genome whose expression is tightly coordinated with that of the nuclear genome. The majority of chloroplast proteins are encoded by nuclear genes, translated in the cytosol as precursor proteins containing a transit sequence at their amino terminus that serves as the entry ticket into chloroplasts.