Ferredoxin biosynthesis in Euglena gracilis.

Analysis of ferredoxin content in cultures of Euglena gracilis grown in the presence of selective antibiotic inhibitors of protein synthesis resulted in the following conclusions: 1. Ferredoxin is synthesized from cytoplasmic (80s-type) ribosomes; cycloheximide, a potent inhibitor of 80s translation completely abolished the synthesis, while the inhibitors of 70s translation chloramphenicol and erythromycin were not effective. In addition, ferredoxin was detected in a streptomycin-bleached mutant that lacks the chloroplast structure and chloroplast DNA. 2. Ferredoxin's transcript is presumably of nuclear origin; rifampicin, an inhibitor of chloroplast DNA-dependent RNA polymerase did not inhibit synthesis, while the streptomycin-bleached mutant continued to synthesize ferredoxin without chloroplast DNA.