抄録
It is known that Gloeobacter violaceus PCC 7421 was branched off at an early stage in the phylogenetic tree of cyanobacteria on basis of the SSU rRNA sequences. This suggests that the organism still retains old properties in photosynthesis. The photosynthetic systems are localized in cytoplasmic membranes. Oxidation of water is carried out in the periplasmic space. In 2003, the whole genome sequence of this organism was reported (Nakamura et al., DNS Res., 2003). Four genes corresponding to minor subunits of PS II RC complex are absent, and several components engaging in water oxidation are not conserved in their amino acid sequences. We observed a few unique properties of PS II and found several defects, for example, this species was not able to grow under strong light. Based on these observations, we will discuss the basics and developments of PS II in cyanobacteria.
