Open AccessCharacterization of group II chaperonins from an acidothermophilic archaeon Picrophilus torridus
Author(s) -
Yamamoto Yohei Y.,
Tsuchida Kanako,
Noguchi Keiichi,
Ogawa Naoki,
Sekiguchi Hiroshi,
Sasaki Yuji C.,
Yohda Masafumi
Publication year - 2016
Publication title -
febs open bio
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.718
H-Index - 31
ISSN - 2211-5463
DOI - 10.1002/2211-5463.12090
Subject(s) - chaperonin , proteostasis , protein folding , chemistry , chaperone (clinical) , folding (dsp implementation) , biophysics , biochemistry , biology , microbiology and biotechnology , medicine , pathology , electrical engineering , engineering
Chaperonins are a type of molecular chaperone that assist in the folding of proteins. Group II chaperonins play an important role in the proteostasis in the cytosol of archaea and eukarya. In this study, we expressed, purified, and characterized group II chaperonins from an acidothermophilic archaeon Picrophilus torridus . Two genes exist for group II chaperonins, and both of the gene products assemble to form double‐ring complexes similar to other archaeal group II chaperonins. One of the Picrophilus chaperonins, Pto CPN α, was able to refold denatured GFP at 50 °C. As expected, Pto CPN α exhibited an ATP ‐dependent conformational change that is observed by the change in fluorescence and diffracted X‐ray tracking ( DXT ). In contrast, Pto CPN α lost its protein folding ability at moderate temperatures, becoming unable to interact with unfolded proteins. At lower temperatures, the release rate of the captured GFP from Pto CPN α was accelerated, and the affinity of denatured protein to Pto CPN α was weakened at the lower temperatures. Unexpectedly, in the DXT experiment, the fine motions were enhanced at the lower temperatures. Taken together, the results suggest that the fine tilting motions of the apical domain might correlate with the affinity of group II chaperonins for denatured proteins.