PSMC6 (proteasome (prosome, macropain) 26S subunit, ATPase 6), also known as P44, p42, SUG2, S10B or CADP44, is a regulatory component of the 26S proteasome. More specifically, PSMC6 is one of the six ATPase subunits of the 19S regulator base. It contains a leucine zipper motif and an AAA (ATPase associated with diverse cellular activities) domain and belongs to the AAA ATPase family of chaperone-like ATPases.