Abstract
Maturation of D1 protein in photosystem II completes after proteolytic processing of carboxyl-terminal extension of precursor protein. Since carboxyl-terminus of mature D1 protein is required for the assembly of 4Mn-1Ca cluster and integration of oxygen evolving complex, the processing is important step for photosynthetic water oxidation. In addition, the processing is speculated to be involved in stabilization of D1 protein; although its functional role has not been fully resolved. D1 protein is well conserved among a wide variety of organisms. However, the absence of C-terminal extension has been reported in some photosynthetic protists of secondary symbiotic origins. The present study is focusing on Dinoflagellate which inherited its plastid from red algae (haptophyte). We found multiple genes coding D1 protein (psbA) in a strain. These psbA genes were characterized from the view points of gene structure and deduced C-terminal sequence of D1 protein.
