Abstract
Photosystem I (PSI) complex in photosynthetic electron transport plays roles in light-harvesting and photochemical reaction. The components and reactions of the complex have been extensively studied. However, little is know on the assembly process. The reasons why little is know on the assembly process are; (1) assembly process is difficult to study in vitro, and (2) constituent components are efficiently and rapidly integrated into a functional complex in vivo. Here we will focus on the chloroplast-encoded Ycf3 and Ycf4 essential for the PSI assembly. Of great interest is that Ycf4 is a component of a large complex containing PsaF, Cop2 as well as Ycf4. In addition, several site-directed mutants of ycf4 genes were generated to get some insight into the assembly process. We have also identified and characterized an assembly intermediate by refined biochemical characterization and pulse-chase protein labeling. We will propose an assembly model for PSI complex.
