ATP-dependent Clp protease proteolytic subunit (ClpP) (ClpP)

Bacterial caseinolytic protease P (ClpP) is a highly conserved serine protease that functions as the proteolytic core of the ATP-dependent Clp protease complex [NIH, 2019; EBI, 2023]. It typically forms a tetradecameric, barrel-shaped structure that sequesters its 14 active sites within an internal chamber to prevent indiscriminate proteolysis [ACS, 2022]. Under normal conditions, ClpP activity is strictly regulated by AAA+ ATPase chaperones, such as ClpX or ClpA, which recognize, unfold, and translocate specific substrates into the chamber [ResearchGate, 2020]. This enzyme is vital for bacterial protein homeostasis, the degradation of misfolded proteins, and the regulation of virulence factors across various pathogens, including Staphylococcus aureus and Mycobacterium tuberculosis [NIH, 2019; ACS, 2022]. As a therapeutic target, ClpP can be modulated by two distinct classes of small molecules: activators and inhibitors [ACS, 2022]. Activators, such as acyldepsipeptides (ADEPs), bind allosterically to open the axial pore and align the catalytic triad, leading to the uncontrolled, ATP-independent degradation of essential proteins and bacterial death [NIH, 2019; ResearchGate, 2020]. Inhibitors, including certain boronates and natural products, block the active site to disrupt protein turnover and attenuate bacterial virulence [ACS, 2022]. A primary challenge in drug development is achieving selectivity for the bacterial enzyme over the human mitochondrial ClpP homolog to minimize off-target toxicity [ResearchGate, 2020; ACS, 2022].

Other names

Caseinolytic protease PClp proteasePeptidase S14Caseinolytic protease proteolytic subunitClpP1ClpP2

Drugs targeting bacterial ClpP function either as allosteric activators or active-site inhibitors. Activators, such as acyldepsipeptides, bind to the chaperone-binding pocket to induce a conformational change that opens the axial pore and aligns the catalytic triad, resulting in the uncontrolled, ATP-independent degradation of essential cellular proteins. Inhibitors bind to the catalytic serine or allosteric sites to block proteolytic activity, thereby disrupting the regulation of virulence factors and essential protein turnover.