K-056. Inhibition of Chlorophyll Synthase of Synechocystis sp. PCC6803 by Bacteriochlorophyllide a

M-K. Lee, J. K. Lee;
Sogang Univ., Seoul, REPUBLIC OF KOREA.

Chlorophyll a synthase and bacteriochlorophyll a synthase attach C20 geranylgerany diphosphate to their substrates chlorophyllide a and bacteriochlorophyllide a, respectively. The activity of Chlorophyll a synthase is largely inhibited by bacteriochlorophyllide a, a possible structural analog of chlorophyllide a. Consistently, the photosynthetic growth of Synechocystis sp. PCC6803 was inhibited by bacteriochlorophyllide a in a dose dependent way. The bacteriochlorophyllide a-mediated inhibition of ChlG activity appears to be competitive.