title: Inter-ring communication is dispensable in the reaction cycle of group II chaperonins.
abstract: Chaperonins are ubiquitous molecular chaperones with the subunit molecular mass of 60kDa. They exist as double-ring oligomers with central cavities. An ATP-dependent conformational change of the cavity induces the folding of an unfolded protein that is captured in the cavity. In the group I chaperonins, which are present in eubacteria and eukaryotic organelles, inter-ring communication takes important role for the reaction cycle. However, there has been limited study on the inter-ring communication in the group II chaperonins that exist in archaea and the eukaryotic cytosol. In this study, we have constructed the asymmetric ring complex of a group II chaperonin using circular permutated covalent mutants. Although one ring of the asymmetric ring complex lacks ATPase or ATP binding activity, the other wild-type ring undergoes an ATP-dependent conformational change and maintains protein-folding activity. The results clearly demonstrate that inter-ring communication is dispensable in the reaction cycle of group II chaperonins.
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Naka, Koganei, Tokyo 184-8588, Japan.
authors.forename: Yohei Y
authors.initials: YY
authors.lastname: Yamamoto
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Naka, Koganei, Tokyo 184-8588, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Abe
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Naka, Koganei, Tokyo 184-8588, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Moriya
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Naka, Koganei, Tokyo 184-8588, Japan.
authors.forename: Mayuno
authors.initials: M
authors.lastname: Arita
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Naka, Koganei, Tokyo 184-8588, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Noguchi
authors.affiliation: Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8566, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Ishii
authors.affiliation: Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198, Japan; CREST Sasaki Team, Japan Science and Technology Agency, Tokyo 102-0076, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sekiguchi
authors.affiliation: CREST Sasaki Team, Japan Science and Technology Agency, Tokyo 102-0076, Japan; Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8561, Japan.
authors.forename: Yuji C
authors.initials: YC
authors.lastname: Sasaki
authors.affiliation: Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Naka, Koganei, Tokyo 184-8588, Japan. Electronic address: yohda@cc.tuat.ac.jp.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yohda
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D001483:Base Sequence; D056385:Group II Chaperonins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D017510:Protein Folding; D019712:Thermococcus / Q000737:chemistry
chemical_list: D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D056385:Group II Chaperonins
keywords: allostery; chaperone; chaperonin; circular permutation; folding