Structure of 20S proteasome from yeast at 2.4 angstrom resolution
Structure of 20S proteasome from yeast at 2.4 angstrom resolution
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DOI：
10.1038/386463a0
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发表时间：
1997-04-03
期刊：
影响因子：
64.8
通讯作者：
Huber, R
中科院分区：
文献类型：
--
作者：
Groll, M;Ditzel, L;Huber, R
酵母20S蛋白酶体的晶体结构表明，其28个蛋白亚基呈（α - 1）型排列。7号，1号…β 7(2)在四个堆叠的环中形成复合物，并占据独特的位置。含有活性位点的颗粒内部只能通过一些非常狭窄的侧入口进入，β型亚基在被蛋白质水解加工组装到颗粒中之前被合成为原蛋白，β 1/PRE3， β 2/PUP1和β 5/PRE2这7个不同的β型亚基中的3个的分型在1号位置的苏氨酸和前序列的最后一个甘氨酸之间被切割，释放活性位点残基Thr 1。这三个β型亚基具有抑制剂结合位点，表明PRE2具有胰凝乳蛋白酶样活性和胰蛋白酶样活性，PRE3具有肽酰谷氨酰肽水解特异性。其他β型亚基被加工成中间形式，表明可能存在额外的非特异性内肽酶活性，这对于肽水解和主要组织相容性复合体I类分子的配体的生成很重要。
The crystal structure of the 20S proteasome from the yeast Saccharomyces cerevisiae shows that its 28 protein subunits are arranged as an (alpha 1...alpha 7, beta 1...beta 7)(2) complex in four stacked rings and occupy unique locations. The interior of the particle, which harbours the active sites, is only accessible by some very narrow side entrances, The beta-type subunits are synthesized as proproteins before being proteolytically processed for assembly into the particle, The proforms of three of the seven different beta-type subunits, beta 1/PRE3, beta 2/PUP1 and beta 5/PRE2, are cleaved between the threonlne at position 1 and the last glycine of the pro-sequence, with release of the active-site residue Thr 1. These three beta-type subunlts have inhibitor-binding sites, indicating that PRE2 has a chymotrypsin-like and a trypsin-like activity and that PRE3 has peptidylglutamyl peptide hydrolytlc specificity, Other beta-type subunits are processed to an intermediate form, indicating that an additional nonspecific endopeptidase activity may exist which is important for peptide hydrolysis and for the generation of ligands for class I molecules of the major histocompatibility complex.