Crystal structure of group II chaperonin in the open state.
Thermosomes are group II chaperonins responsible for protein refolding in an ATP-dependent manner. Little is known regarding the conformational changes of thermosomes during their functional cycle due to a lack of high-resolution structure in the open state. Here, we report the first complete crystal structure of thermosome (rATcpnβ) in the open state from Acidianus tengchongensis. There is a ∼30° rotation of the apical and lid domains compared with the previous closed structure. Besides, the structure reveals a conspicuous hydrophobic patch in the lid domain, and residues locating in this patch are conserved across species. Both the closed and open forms of rATcpnβ were also reconstructed by electron microscopy (EM). Structural fitting revealed the detailed conformational change from the open to the closed state. Structural comparison as well as protease K digestion indicated only ATP binding without hydrolysis does not induce chamber closure of thermosome.
Huo
Yanwu
Y
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
Hu
Zhongjun
Z
Zhang
Kai
K
Wang
Li
L
Zhai
Yujia
Y
Zhou
Qiangjun
Q
Lander
Gabe
G
Zhu
Jiang
J
He
Yongzhi
Y
Pang
Xiaoyun
X
Xu
Wei
W
Bartlam
Mark
M
Dong
Zhiyang
Z
Sun
Fei
F
D041541:Acidianus / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000737:chemistry / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D020285:Cryoelectron Microscopy; D003460:Crystallization; D004591:Electrophoresis, Polyacrylamide Gel; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D056405:Thermosomes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014961:X-Ray Diffraction
D019843:Archaeal Proteins; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D056405:Thermosomes