Component of the chloroplastic Clp protease core complex which consist of at least 16 proteins: ClpP4 (3 copies), ClpP5 (3 copies), ClpR4 (2 copies), ClpP1 (1 copy), ClpP6 (1 copy), ClpR2 (1 copy), ClpS1 (1 copy), ClpS2 (1 copy) and 3 copies of ClpP3 and/or ClpR1 and/or ClpR3.