Evidence for a role of ClpP in the degradation of the chloroplast cytochrome b(6)f complex.

摘要: In the green alga Chlamydomonas reinhardtii, ClpP protease is encoded by an essential chloroplast gene. Mutating its AUG translation initiation codon to AUU reduced accumulation 25 45% of that wild type. Both mature protein and putative precursor containing insertion sequence were present in amounts. Attenuation did not affect growth rates under normal conditions but restricted ability cells adapt elevated CO2 levels. It also affected rate degradation cytochrome b6f complex thylakoid membrane two experimental situations: (1) during nitrogen starvation, (2) mutants deficient Rieske iron–sulfur protein. The level controls steady state a mutated version contrast, attenuation rescue fully unassembled subunits other mutants. We conclude proteolytic disposal or partially assembled controlled Clp protease.