Kopp F, Hendil K B, Dahlmann B, Kristensen P, Sobek A, Uerkvitz W
Diabetes Forschungsinstitut, Düsseldorf, Germany.
Proc Natl Acad Sci U S A. 1997 Apr 1;94(7):2939-44. doi: 10.1073/pnas.94.7.2939.
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.
在人20S蛋白酶体中，七种不同的α型亚基和七种不同的β型亚基各有两个拷贝组装在一起，形成一个由四个七元环组成的堆叠结构，其总体结构为α(1 - 7)、β(1 - 7)、β(1 - 7)、α(1 - 7)。通过免疫电子显微镜和相邻亚基的化学交联，我们确定了蛋白酶体中各个亚基的位置。拓扑结构表明，对于胰蛋白酶样、糜蛋白酶样和谷氨酰胺后切割活性而言，被认为形成活性位点的β型亚基对是最邻近的邻居。
