Abstract
To search for new member of C4 photosynthesis, we have isolated several C4 plant-abundantly expressed genes by transcriptome analysis between Flaveria trinervia (C4) and F. pringlei (C3). Among them we found out a novel gene, encoding a CP12 domain-containing protein, named FtCP12L. Its biochemical function was totally unknown in C4 plants. Here we will show our trial to identify the binding partner of the FtCP12L. The recombinant His-tagged FtCP12L protein was incubated with crude protein extract from F. trinervia leaves under the oxidative condition. Using the Ni-chelating column, recombinant protein was affinity purified and co-eluted proteins were analyzed with the SDS-PAGE. We found two ca. 43-kDa- and ca. 65-kDa-protein bands as candidates and the former was recognized with the antibody for phosphoribulokinase. These results indicate that the FtCP12L forms a novel protein complex, including phosphoribulokinase and the 64-kDa-protein in C4 Flaveria.
