Dahlmann B, Kopp F, Kristensen P, Hendil K B
Diabetes Forschungsinstitut, Auf' m Hennekamp 65, Düsseldorf, D-40225, Germany.
Arch Biochem Biophys. 1999 Mar 15;363(2):296-300. doi: 10.1006/abbi.1999.1104.
The arrangement of subunits in human 20S proteasomes was recently determined by us by immunoelectron microscopy and chemical cross-linking. The positions of 4 of the 14 subunits differed from those found in the yeast proteasome by X-ray crystallography. Double labeling of human 20S proteasomes with antibodies to subunits C2 and C5 has now shown that these subunits are nearest neighbors. The result contradicts our published model for the human proteasome but is in accordance with the subunit arrangement in yeast proteasomes, suggesting that yeast and human proteasomes most probably have identical subunit arrangements. Immunoelectron microscopy also showed that the C-terminal extension at the human C2 subunit is flexible but takes up a well-defined position in the proteasome.
我们最近通过免疫电子显微镜和化学交联确定了人20S蛋白酶体中亚基的排列方式。14个亚基中有4个亚基的位置与通过X射线晶体学在酵母蛋白酶体中发现的位置不同。现在，用人蛋白酶体亚基C2和C5的抗体进行双重标记表明，这些亚基是紧邻的。该结果与我们发表的人蛋白酶体模型相矛盾，但与酵母蛋白酶体中的亚基排列一致，这表明酵母和人蛋白酶体很可能具有相同的亚基排列。免疫电子显微镜还显示，人C2亚基的C末端延伸部分是灵活的，但在蛋白酶体中占据一个明确的位置。
