endopeptidase Clp complex

Definition

Target type: cellularcomponent

A protein complex comprised of members of the ClpX, ClpC, ClpD, ClpP or ClpR protein families. ClpPs are the proteolytic subunit of active complexes, and ClpA and ClpX form the regulatory subunits. Enzymatically active and inactive complexes can form. [GOC:mah, PMID:11352464]

The Clp complex is a ubiquitous and essential protease system found in bacteria, archaea, and eukaryotes. It plays a crucial role in protein quality control, degrading misfolded, damaged, or unnecessary proteins. The Clp complex is composed of two major components: a barrel-shaped protease subunit (ClpP) and an ATPase chaperone subunit (ClpX, ClpA, or ClpC).

The ClpP subunit is a cylindrical structure that houses the proteolytic active site. It forms a tetradecamer composed of two heptameric rings stacked back-to-back. Each ring contains seven identical ClpP monomers. The active site of each monomer is located at the interface between two subunits within the ring.

The ClpX, ClpA, or ClpC ATPase subunit serves as a substrate recognition and unfolding machinery. It is a hexameric ring that associates with the ClpP ring at one end. The ATPase subunits recognize and bind to specific degradation signals on target proteins. They use the energy derived from ATP hydrolysis to unfold the substrate protein and thread it through the central channel of the ClpP ring.

The Clp complex is highly regulated to ensure that only the appropriate proteins are degraded. Specific regulatory mechanisms include:

* **Substrate recognition:** ClpX, ClpA, or ClpC subunits possess distinct substrate-binding domains that recognize specific degradation signals on target proteins.
* **ATP hydrolysis:** The ATPase activity of the ClpX, ClpA, or ClpC subunits is essential for unfolding and threading the substrate into the ClpP chamber.
* **Protein interactions:** The Clp complex interacts with other cellular components, such as chaperones and regulatory proteins, to coordinate its activity.

The cellular component of the endopeptidase Clp complex is the **Clp protease complex** itself, which is a multi-protein assembly composed of the ClpP protease subunit and the ATPase chaperone subunit. This complex resides in various cellular locations, including the cytoplasm, mitochondria, and chloroplasts, depending on the organism.'
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Proteins (2)

Compounds (3)