Denatured proteins facilitate the formation of the football-shaped GroEL-(GroES)2 complex

• Published in: Biochemical journal Vol. 427; no. 2; p. 247
• Main Authors: Sameshima, Tomoya, Iizuka, Ryo, Ueno, Taro, Funatsu, Takashi
• Format: Journal Article
• Language: English
• Published: England 15.04.2010
• Subjects: Adenosine Diphosphate - pharmacology; Adenosine Triphosphate - pharmacology; Chaperonin 10 - chemistry; Chaperonin 10 - metabolism; Chaperonin 60 - chemistry; Chaperonin 60 - metabolism; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - metabolism; Fluorescence Resonance Energy Transfer; Kinetics; Multiprotein Complexes - chemistry; Protein Binding; Protein Conformation; Protein Denaturation
• DOI: 10.1042/BJ20091845

Controversy exists over whether the chaperonin GroEL forms a GroEL-(GroES)2 complex (football-shaped complex) during its reaction cycle. We have revealed previously the existence of the football-shaped complex in the chaperonin reaction cycle using a FRET (fluorescence resonance energy transfer) assay [Sameshima, Ueno, Iizuka, Ishii, Terada, Okabe and Funatsu (2008) J. Biol. Chem. 283, 23765-23773]. Although denatured proteins alter the ATPase activity of GroEL and the dynamics of the GroEL-GroES interaction, the effect of denatured proteins on the formation of the football-shaped complex has not been characterized. In the present study, a FRET assay was used to demonstrate that denatured proteins facilitate the formation of the football-shaped complex. The presence of denatured proteins was also found to increase the rate of association of GroES to the trans-ring of GroEL. Furthermore, denatured proteins decrease the inhibitory influence of ADP on ATP-induced association of GroES to the trans-ring of GroEL. From these findings we conclude that denatured proteins facilitate the dissociation of ADP from the trans-ring of GroEL and the concomitant association of ATP and the second GroES.