Abstract
In higher plant PSII, the 33 kDa protein directly binds to PSII, but the 23 and 17 kDa proteins associate with PSII through the 33 kDa protein and through both 33 and 23 kDa proteins, respectively. In contrast, in green algal PSII, each of the 33, 23 and 17 kDa proteins directly binds to PSII independent upon the other extrinsic proteins (Suzuki et al. P.C.P. in press). In this study, we performed cross-reconstitution experiments of these extrinsic proteins with green algal and higher plant PSIIs to clarify the difference of their binding properties. The results showed that higher plant 23 and 17 kDa proteins directly bind to green algal PSII by itself, while green algal 23 and 17 kDa proteins cannot directly bind to higher plant PSII. This indicates that the difference of binding properties of their extrinsic proteins to PSII is responsible for intrinsic proteins.
