title: Denatured proteins facilitate the formation of the football-shaped GroEL-(GroES)2 complex.
abstract: 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.
authors.affiliation: The University of Tokyo, Bunkyo-ku, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Sameshima
authors.forename: Ryo
authors.initials: R
authors.lastname: Iizuka
authors.forename: Taro
authors.initials: T
authors.lastname: Ueno
authors.forename: Takashi
authors.initials: T
authors.lastname: Funatsu
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D018835:Chaperonin 10 / Q000737:chemistry* / Q000378:metabolism; D018834:Chaperonin 60 / Q000737:chemistry* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D007700:Kinetics; D046912:Multiprotein Complexes / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D011489:Protein Denaturation
chemical_list: D018835:Chaperonin 10; D018834:Chaperonin 60; D029968:Escherichia coli Proteins; D046912:Multiprotein Complexes; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate