PA700 proteasome activator

Fig. n.3. Non-canonical functions of PA700 in the regulation of proteasome activity. A)... 

Kopp, E., Dahlmann, B., and Kuehn, L. Reconstitution of hybrid proteasomes from purified PA700-20 S complexes and PA28alphabeta activator ultrastructure and peptidase activities. JMol Biol 2001, 313, 465-71. 

The degradation of ubiquitinated proteins by the 26S proteasome requires PA700-catalyzed ATP hydrolysis. How is proteolysis mechanistically linked to ATPase activity Despite the fundamental nature of this question, a detailed answer is unknown. As described below, ATP hydrolysis probably mediates multiple elements... 

G. N. Identification, purification, and characterization of a high-molecular weight, ATP-dependent activator (PA700) of the 20S proteasome. J. 

Hendil, K.B., Khan, S., Tanaka, K., Simultaneous Binding of PA28 and PA700 activators to 20 S proteasomes. Biochem. 

Fig 37.5. The proteasome and cap proteins. The cap proteins (PA700 and PA28) regulate the activity of this proteolytic complex by recruiting to the complex the substrates for proteolysis. The ATP requirement is to unfold and denature the proteins targeted for destruction, although the PA28 protease complex does not require ATP. 

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