The protein-folding activity of chaperonins correlates with the symmetric GroEL14(GroES7)2 heterooligomer.
Chaperonins GroEL and GroES form, in the presence of ATP, two types of heterooligomers in solution: an asymmetric GroEL14GroES7 "bullet"-shaped particle and a symmetric GroEL14(GroES7)2 "football"-shaped particle. Under limiting concentrations of ATP or GroES, excess ADP, or in the presence of 5'-adenylyl imidodiphosphate, a correlation is seen between protein folding and the amount of symmetric GroEL14(GroES7)2 particles in a chaperonin solution, as detected by electron microscopy or by chemical crosslinking. Kinetic analysis suggests that protein folding is more efficient when carried out by a chaperonin solution populated with a majority of symmetric GroEL14(GroES7)2 particles than by a majority of asymmetric GroEL14GroES7 particles. The symmetric heterooligomer behaves as a highly efficient intermediate of the chaperonin protein folding cycle in vitro.
Azem
A
A
Department of Botany, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Israel.
Diamant
S
S
Kessel
M
M
Weiss
C
C
Goloubinoff
P
P
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D018835:Chaperonin 10 / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018834:Chaperonin 60 / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018833:Chaperonins / Q000378:metabolism*; D003432:Cross-Linking Reagents; D007700:Kinetics; D046911:Macromolecular Substances; D008291:Malate Dehydrogenase / Q000737:chemistry / Q000378:metabolism; D008929:Mitochondria, Heart / Q000201:enzymology; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry / Q000378:metabolism; D013552:Swine
D018835:Chaperonin 10; D018834:Chaperonin 60; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D008291:Malate Dehydrogenase; D018833:Chaperonins; D012273:Ribulose-Bisphosphate Carboxylase