Dubiel W, Ferrell K, Pratt G, Rechsteiner M
Department of Biochemistry, University of Utah School of Medicine, Salt Lake City 84132.
J Biol Chem. 1992 Nov 15;267(32):22699-702.
Ubiquitinated proteins are degraded by a 26 S ATP-dependent protease. SDS-polyacrylamide gel electrophoresis analysis of the purified 26 S enzyme reveals more than 20 polypeptides ranging in apparent molecular masses from 20 to 110 kDa. Although many of the subunits smaller than 30 kDa are members of the multicatalytic protease family, the identity and function of the larger polypeptides have remained unknown. We report here the cDNA sequence for subunit 4, a 51-kDa chain of the 26 S protease. Subunit 4 belongs to a recently identified eukaryotic ATPase family, which includes proteins involved in peroxisome formation, secretion, and human immunodeficiency virus gene expression. Subunit 4 also shows weak similarity to ClpA, the ATP-binding subunit of the Escherichia coli protease, Clp.
泛素化蛋白由一种26S ATP依赖性蛋白酶降解。对纯化的26S酶进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析，可发现20多种多肽，其表观分子量在20至110 kDa之间。虽然许多小于30 kDa的亚基是多催化蛋白酶家族的成员，但较大多肽的身份和功能仍不清楚。我们在此报告26S蛋白酶51-kDa链的亚基4的cDNA序列。亚基4属于最近鉴定出的真核ATP酶家族，该家族包括参与过氧化物酶体形成、分泌和人类免疫缺陷病毒基因表达的蛋白质。亚基4与大肠杆菌蛋白酶Clp的ATP结合亚基ClpA也有微弱的相似性。
