CRYSTAL-STRUCTURE OF THE 20S PROTEASOME FROM THE ARCHAEON T-ACIDOPHILUM AT 3.4-ANGSTROM RESOLUTION
CRYSTAL-STRUCTURE OF THE 20S PROTEASOME FROM THE ARCHAEON T-ACIDOPHILUM AT 3.4-ANGSTROM RESOLUTION
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DOI：
10.1126/science.7725097
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发表时间：
1995-04-28
期刊：
影响因子：
56.9
通讯作者：
HUBER, R
中科院分区：
文献类型：
--
作者：
LOWE, J;STOCK, D;HUBER, R
X射线晶体学分析通过同构替换和环状平均进行了X射线晶体学分析阐明了来自嗜热嗜酸菌的蛋白酶体的三维结构。建立原子模型并精制到晶体学R系数22.1％。 673-kilodalton蛋白酶复合物由14个副本组成，分别是两个不同的亚基，Alpha和beta，形成了四个堆叠环的桶形结构。两个内环每个环由七个β亚基组成，两个外环由七个α亚基组成。狭窄的通道控制对三个内部隔室的访问。 Alpha（7）β（7）β（7）Alpha（7）亚基组件具有72分组对称性。 Alpha和Beta亚基的结构相似，由两个反平行β板的核心组成，两侧两侧是Alpha螺旋。肽醛抑制剂的结合标记了β亚基氨基末端中心腔中的活性位点，并提出了一种新型的蛋白水解机制。
The three-dimensional structure of the proteasome from the archaebacterium Thermoplasma acidophilum has been elucidated by x-ray crystallographic analysis by means of isomorphous replacement and cyclic averaging. The atomic model was built and refined to a crystallographic R factor of 22.1 percent. The 673-kilodalton protease complex consists of 14 copies of two different subunits, alpha and beta, forming a barrel-shaped structure of four stacked rings. The two inner rings consist of seven beta subunits each, and the two outer rings consist of seven alpha subunits each. A narrow channel controls access to the three inner compartments. The alpha(7) beta(7) beta(7) alpha(7) subunit assembly has 72-point group symmetry. The structures of the alpha and beta subunits are similar, consisting of a core of two antiparallel beta sheets that is flanked by alpha helices on both sides. The binding of a peptide aldehyde inhibitor marks the active site in the central cavity at the amino termini of the beta subunits and suggests a novel proteolytic mechanism.