Ribulose bisphosphate carboxylase from a mutant strain ofChlamydomonas reinhardiideficient in chloroplast ribosomes

摘要

Theac-20mutant strain of the unicellular green alga,Chlamydomonas reinhardii, lacks both chloroplast ribosomes and ribulose bisphosphate carboxylase activity when grown on organic medium. Under these conditions, the cells do not posses pools of either the large or small subunit of this enzyme. When transferred to inorganic medium, the carboxylase activity recovers. During this recovery,de novosynthesis of both subunits occurs. Synthesis of both subunits is inhibited by chloramphenicol even when possible free subunit pools rather than just the subunits incorporated into whole enzyme are examined.