Abstract
The gene ycf33 is identified in the chloroplast genomes so far analysed and is also found in the genomes of cyanobacteria. It is also encoded in the nuclear genome of A. thaliana. We have constructed a deletion mutant of the gene in Synechocystis 6803 and found that the cyclic electron flow around PSI is affected.
Rereduction rate of P700 was not affected in the presence of DCMU in both the mutant and wild type.HgCl2 inhibited rereduction of P700 in both the mutant and the wild type, but the mutant was more sensitive to the reagent. The effective concentration was lower when the cells were shifted from 3%CO2 to air (0.03%CO2) for 24h. When the cells were grown in the air, HgCl2 showed almost no effect on cyclic electron transport. These results suggest that the pathway which is sensitive to HgCl2 and expressed under high CO2 is mainly used in the mutant.
