NCIt definition : Ubiquitinated proteins are degraded by a 26S ATP-dependent protease complex, composed
of a 20S catalytic proteasome and two 19S PA700 regulatory modules. The multi-subunit
PA700 complex binds two sites of the 20S proteasome and is composed of at least six
related ATPases and approximately fifteen non-ATPase polypeptides. Each of the ATPases,
PSMC1-6, contains an AAA (ATPases associated with diverse cellular activities) domain.
A protein complex containing p42 and p50 enhances PA700 activation of the proteasome.;