This generates a proton gradient across the thylakoid membrane.
Chloroplasts are made up of stacks of thylakoid disks; a stack of thylakoid disks; a stack of thylakoid disks is called a granum.
The transit peptide is very similar in structure to a family of nuclear proteins imported into the thylakoid lumen.
The dimeric PSII supercomplex used for this study was isolated from spinach chloroplast thylakoid membranes.
A summary slide is shown in Fig 1: Figure 1. Pathways for the targeting of thylakoid lumen proteins in chloroplasts.