The state of oligomerization of Rubisco controls the rate of LSU translation in Chlamydomonas reinhardtii

摘要: Ribulose 1,5-bisphosphate Carboxylase/Oxygenase (Rubisco) is a key enzyme for photosynthesis-driven life on Earth. While present in all photosynthetic organisms, its most prominent form hetero-oligomer which Small Subunit (SSU) stabilizes the core of built from Large Subunits (LSU), yielding, after chaperone-assisted multistep assembly, LSU8SSU8 hexadecameric holoenzyme. Here we use Chlamydomonas reinhardtii, and combination site-directed mutants, to dissect biogenesis pathway Rubisco vivo. We identify assembly intermediates, two LSU associated with RAF1 chaperone. Using genetic biochemical approaches further unravel major regulation process during places translation large subunit under control ability assemble small subunit, by mechanism Control Epistasy Synthesis (CES). Altogether this leads us propose model where last intermediate, an octameric LSU8-RAF1 complex delivers SSU enzyme, converts regulator able exert negative feed-back initiation LSU, when not available.