Table 1.

Comparison between 26S proteasomes and Clp protease.

Issues/Characteristics	26S Proteasomes	Clp Protease
Location	Cytoplasm and nucleus	Plastid and mitochondria
2.Components	19S regulatory particle and 20S core particle	Chaperone subunit and proteolytic subunit
3.Regulatory particle or Chaperone	19S regulatory particle, hexameric ring	Chaperone subunit, hexameric ring
4.Proteolytic subunit	20S core particle, heptagonal barrel-shaped ring	Proteolytic subunit, tetradecameric barrel-shaped ring
5.Components of Regulatory particle (RP) or Chaperone	Regulatory particle consists of base and lid. Base has six ATPase subunits (Rpt1-Rpt6) and two non-ATPase subunits (Rpn1 and Rpn2). Lid contains eight non-ATPase subunits (RPN3, 5–9, 11, and 12)	ClpC1, ClpC2, and ClpD constitute the chaperone subunit (in Arabidopsis thaliana)
6.Components of Proteolytic subunit	Four ring. Inner two rings are β catalytic rings (β1-7) and outer two rings are α rings (α1-7)	ClpP1, ClpP3, ClpP4, ClpP5, and ClpP6 constitute the proteolytic subunit (in Arabidopsis thaliana)
7.Linker or adapters	Rpn10 and Rpn13 serve as linker between lid and base	ClpS1 and ClpF serve as adapter for ClpC (in Arabidopsis thaliana)