Synthesis and Turnover of the Chloroplast Coupling Factor 1 in Chlamydomonas reinhardi

Abstract

Studies on the biosynthesis of the chloroplast coupling factor 1 (CF(1)) in Chlamydomonas reinhardi have been initiated. The ratio of CF(1) to chlorophyll in the cell was shown to be independent of the density of the culture. No turnover of assembled CF(1) could be detected, thus suggesting that CF(1) was synthesized at a rate equivalent to that of net chlorophyll synthesis. A lag of between 5 to 7 minutes in the incorporation of radioactive precursor sulfate into assembled CF(1) was measureable. This puts an upper limit on the pool size of any precursor to the assembled CF(1) complex. The pool size is estimated to be equivalent to 1% of the total CF(1) in the cell.