ATP binding is critical for the conformational change from an open to closed state in archaeal group II chaperonin.
Group II chaperonins, found in archaea and in eukaryotic cytosol, do not have a co-chaperonin corresponding to GroES. Instead, it is suggested that the helical protrusion extending from the apical domain acts as a built-in lid for the central cavity and that the opening and closing of the lid is regulated by ATP binding and hydrolysis. However, details of this conformational change remain unclear. To investigate the conformational change associated with the ATP-driven cycle, we conducted protease sensitivity analyses and tryptophan fluorescence spectroscopy of alpha-chaperonin from a hyperthermophilic archaeum, Thermococcus strain KS-1. In the nucleotide-free or ADP-bound state, the chaperonin, especially in the helical protrusion region, was highly sensitive to proteases. Addition of ATP and ammonium sulfate induced the transition to the relatively protease-resistant form. The fluorescence intensity of the tryptophan residue introduced at the tip of the helical protrusion was enhanced by the presence of ATP or ammonium sulfate. We conclude that ATP binding induces the conformational change from the lid-open to lid-closed form in archaeal group II chaperonin.
Iizuka
Ryo
R
Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan.
Yoshida
Takao
T
Shomura
Yasuhito
Y
Miki
Kunio
K
Maruyama
Tadashi
T
Odaka
Masafumi
M
Yohda
Masafumi
M
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism* / Q000494:pharmacology; D000645:Ammonium Sulfate / Q000494:pharmacology; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018833:Chaperonins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D005453:Fluorescence; D006868:Hydrolysis; D016297:Mutagenesis, Site-Directed; D011188:Potassium / Q000008:administration & dosage; D011487:Protein Conformation; D017510:Protein Folding; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship; D019712:Thermococcus / Q000737:chemistry; D014364:Tryptophan / Q000737:chemistry
D001426:Bacterial Proteins; D000244:Adenosine Diphosphate; D014364:Tryptophan; D000255:Adenosine Triphosphate; D010450:Endopeptidases; D018833:Chaperonins; D011188:Potassium; D000645:Ammonium Sulfate