Subunit arrangement in the human 20S proteasome.
In human 20S proteasomes two copies of each of seven different alpha-type and seven different beta-type subunits are assembled to form a stack of four seven-membered rings, giving the general structure alpha(1-7), beta(1-7), beta(1-7), alpha(1-7). By means of immunoelectron microscopy and chemical crosslinking of neighboring subunits, we have determined the positions of the individual subunits in the proteasome. The topography shows that for the trypsin-like, the chymotrypsin-like, and the postglutamyl cleaving activities, the pairs of beta type subunits, which are thought to form active sites, are nearest neighbors.
Kopp
F
F
Diabetes Forschungsinstitut, Düsseldorf, Germany.
Hendil
K B
KB
Dahlmann
B
B
Kristensen
P
P
Sobek
A
A
Uerkvitz
W
W
D000595:Amino Acid Sequence; D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D011487:Protein Conformation; D013329:Structure-Activity Relationship
D009097:Multienzyme Complexes; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex