Crystal structure of the thermosome, the archaeal chaperonin and homolog of CCT
Crystal structure of the thermosome, the archaeal chaperonin and homolog of CCT
复制标题
DOI：
10.1016/s0092-8674(00)81152-6
复制
发表时间：
1998-04-03
期刊：
影响因子：
64.5
通讯作者：
Steinbacher, S
中科院分区：
文献类型：
--
作者：
Ditzel, L;Löwe, J;Steinbacher, S
我们以2.6埃的分辨率测定了嗜酸乳杆菌中的热体--古生菌二族伴侣蛋白的晶体结构。真核细胞伴侣蛋白CCT/TIC的十六聚体同源物显示(αβ)(4)(αβ)(4)亚基组装。结构域折叠与GroEL同源，但形成了一种新型的环间接触。结构域排列类似于GroEL-Groes顺式环。部分顶端结构域形成一个盖子，形成一个封闭的构象。该盖子取代了CCT/TIRE系统中所缺少的小袋样辅伴素。中央空腔有一个与蛋白质折叠有关的极表面。过渡态类似物MS-ADP-AIF(3)的结合表明闭合构象对应于ATP形式。
We have determined to 2.6 Angstrom resolution the crystal structure of the thermosome, the archaeal group II chaperonin from T. acidophilum. The hexadecameric homolog of the eukaryotic chaperonin CCT/TRiC shows an (alpha beta)(4)(alpha beta)(4) subunit assembly. Domain folds are homologous to GroEL but form a novel type of inter-ring contact. The domain arrangement resembles the GroEL-GroES cis-ring. Parts of the apical domains form a lid creating a closed conformation. The lid substitutes for a GroES-like cochaperonin that is absent in the CCT/TRiC system. The central cavity has a polar surface implicated in protein folding. Binding of the transition state analog MS-ADP-AIF(3) suggests that the closed conformation corresponds to the ATP form.